Impact of kerosene space heaters on indoor air quality.

In recent years, the use of kerosene space heaters as additional or principal heat source has been increasing, because these heaters allow a continuous control on the energy cost. These devices are unvented, and all combustion products are released into the room where the heaters are operated. The indoor air quality of seven private homes using wick-type or electronic injection-type kerosene space heaters was investigated. Concentrations of CO, CO2, NOx, formaldehyde and particulate matter (0.02-10 µm) were measured, using time-resolved instruments when available. All heaters tested are significant sources of submicron particles, NOx and CO2. The average NO2 and CO2 concentrations are determined by the duration of use of the kerosene heaters. These results stress the need to regulate the use of unvented combustion appliances to decrease the exposure of people to air contaminants.

Emission factors of gaseous pollutants from recent kerosene space heaters and fuels available in France in 2010.

UNLABELLED: Laboratory measurements of the gaseous emission factors (EF) from two recent kerosene space heaters (wick and injector) with five different fuels have been conducted in an 8-m(3) environmental chamber. The two heaters tested were found to emit mainly CO(2), CO, NO, NO(2), and some volatile organic compounds (VOCs). NO(2) is continuously emitted during use, with an EF of 100-450 µg per g of consumed fuel. CO is normally emitted mainly during the first minutes of use (up to 3 mg/g). Formaldehyde and benzene EFs were quantified at 15 and 16 µg/g, respectively, for the wick heater. Some other VOCs, such as 1,3-butadiene, were detected with lower EFs. We demonstrated the unsuitability of a 'biofuel' containing fatty acid methyl esters for use with the wick heater, and that the accumulation of soot on the same heater, whatever the fuel, leads to a dramatic increase in the CO EF, up to 16 mg/g, which could be responsible for chronic and acute CO intoxications. PRACTICAL IMPLICATIONS: Our results show that in spite of new technologies and emission standards for unvented kerosene space heaters, as well as for the fuels, the use of these heaters in indoor environments still leads to NO(x) levels in excess of current health recommendations. Whereas injection heaters generate more nitrogen oxides than wick heaters, prolonged use of the latter leads to a soot buildup, concomitant with high CO emissions, which could be responsible for acute and chronic intoxications. The use of a biofuel in a wick heater is also of concern. Maintenance of the heaters and adequate ventilation of the room during use of kerosene space heaters are therefore of prime importance to reduce personal exposure.

MR imaging of fetal cerebral anomalies.

BACKGROUND: Prenatal diagnosis of fetal brain anomalies relies mainly upon ultrasonography. However, even in the most experienced hands, the technique has limitations for some difficult diagnoses. MRI is an excellent imaging modality for the paediatric and adult brain. OBJECTIVE: To assess the value of prenatal MRI when a cerebral anomaly was detected by US and where the prognosis depended on the identification of other anomalies undetectable by US, or where fetuses were at risk for a CNS lesion even when the US was normal. MATERIALS AND METHODS: Four hundred prenatal MRI examinations were performed since 1988, and confirmed by postnatal follow-up or pathological examination. Two-thirds of the examinations were performed after 25 weeks of gestation, one-third between 21 and 26 weeks. Fetal immobilisation was obtained by maternal premedication with flunitrazepam, administered orally 1 h before the examination. The examinations were performed on 1.5 T scanners using one or two surface coils. RESULTS: Prenatal MRI allowed the diagnosis of serious unsuspected lesions such as neuronal migration disorders, ischaemic and haemorrhagic lesions and the abnormalities observed in tuberous sclerosis. It helped to characterise ventricular dilatation and anomalies of the corpus callosum and of the posterior fossa. CONCLUSIONS: MRI is a valuable complementary tool when prenatal US is incomplete, doubtful or limited. Prenatal MRI is particularly useful for the detection of ischaemic and haemorrhagic lesions, neuronal migration disorders and tuberous sclerosis lesions. Detection of these associated anomalies worsens the fetal prognosis, has medico-legal implications and modifies obstetric management. Normal prenatal MRI does not exclude an anomaly.

Percutaneous transluminal angioplasty of renal artery stenosis in children.

Twenty percutaneous transluminal renal angioplasties were performed on 16 children (mean age 8.7 years) with hypertension secondary to renal artery stenosis (RAS). The aetiologies were neurofibromatosis (n = 1), Williams syndrome (n = 2), Takayasu arteritis (n = 1) and fibromuscular dysplasia (n = 12). The stenosis was isolated proximal or distal in 13 cases and multiple in 3 cases. Angioplasty resulted in a complete cure without medical treatment in 9 cases. Angioplasty allowed a reduction of medical treatment in two single stenoses, but was ineffective in all cases of multiple stenoses. Our findings show that angioplasty of RAS in children is an effective treatment when the stenosis is isolated, with a 69 % success rate. It seems ineffective in case of multiple stenoses (three cases).

Sphenoid sinus localization of multiple myeloma revealing evolution from benign gammopathy.

BACKGROUND: Plasma-cell neoplasms of the head and neck include extramedullary plasmacytoma and solitary plasmocytoma of bone or may represent a local manifestation of multiple myeloma. Involvement of sphenoid sinus has been rarely reported in multiple myeloma. METHODS: We present the case of a 77-year-old man with a 3-year-history of benign monoclonal IgG-lambda gammopathy who developed left sixth-nerve palsy and malaise. RESULTS: Computed tomography scan and magnetic resonance imaging scan disclosed a large soft-tissue mass of the sphenoid sinus with bone destruction. Sphenoid sinus biopsy revealed an IgG monoclonal plasma cell neoplasm. Diagnosis of multiple myeloma stage IA was then established. CONCLUSIONS: Diagnosis of plasma-cell neoplasm should be considered in sphenoid sinus tumors and depends upon histologic examination. This case enlightens the relationships between monoclonal benign gammopathy and plasma-cell neoplasms of the head and neck which constitute a continuum of B-cell lymphoproliferative disorders.

Subdural sarcoma associated with chronic subdural hematoma. Report of two cases and review of the literature.

The authors report the cases of two children who presented in the first months of life with progressive macrocrania related to chronic pericerebral fluid collection. This condition resolved spontaneously without treatment after a few months in the first case, whereas it required several aspirations of blood-stained fluid via the fontanel in the second case. Both patients developed normally without evidence of disease in the earliest years of life and presented at the ages of 3 1/2 and 4 1/2 years, respectively, with symptoms and signs of rapidly progressing intracranial hypertension. In both cases contrast-enhanced computerized tomography and magnetic resonance imaging revealed masses in the subdural space of the skull base and the cranial vault associated with significant subdural fluid collections. In the first case the lesion was misdiagnosed in the initial phase and treated, by means of multiple craniotomies, as an organized subdural hematoma. After a diagnosis of liposarcoma had been made, the patient was treated with chemotherapy, which resulted in a good resolution of the lesions at 3-month follow-up review. In the second case a biopsy allowed the diagnosis of fibrohistiocytic sarcoma and the patient was treated with chemotherapy. The authors review the literature of the few reported cases and discuss the possible pathophysiological association between pericerebral fluid collection and the subsequent development of a subdural sarcoma.

Vein of Galen vascular malformations in infants: clinical, radiological and therapeutic aspect.

A series of 14 vein of Galen vascular malformations diagnosed in the pediatric populations and treated at the Hospital for Sick Children-Necker, Paris, between 1988 and 1994 is presented. Five of the patients were diagnosed in the neonatal period, of whom 4 presented with life-threatening, intractable cardiac decompensation and high-flow arteriovenous fistulae. Embolization was performed on vital indications in 4 patients during the first week after birth. One embolization failed with fatal outcome. Of the 3 who were embolized, 2 succumbed within 1 week and 1 survived with marked improvement of cardiac symptoms. The older children presented with hydrocephalus and neurologic symptoms. The 10 patients older than 1 year were embolized. These procedures were successful in 90 %, with hemodynamic stabilization and improvement of clinical symptoms. In this group the mortality rate was 10 %. The total mortality rate was 29 %. Hydrocephalus was secondary to a compression of the Sylvian aqueduct in 44 % of cases. Five patients had ventricular drainage before embolization followed by a staged elective embolization. Transarterial embolizations were performed in 11 patients, whereas 2 patients were embolized via the transvenous route.

Lumbar spinal cord motion measurement with phase-contrast MR imaging in normal children and in children with spinal lipomas.

We assessed the normal movement of the lumbar spinal cord using phase-contrast MR imaging, and also the movement of the spinal cord in patients with spinal lipoma pre- and postoperatively. Phase-contrast MR imaging proved to be a valuable tool in this context.

[Spinal cord toxoplasmosis and AIDS]. / Toxoplasmose médullaire et SIDA.

Toxoplasmosis is the most common brain parasitic infection in acquired immunodeficiency syndrome (AIDS). Spinal cord localisations are still rare (2 cases with cerebral involvement, 2 cases without). A case of both spinal cord and cerebral involvement is reported. MR imaging was performed because of sensory level (L1). A focal conus medullaris enlargement was seen, iso intense on T1 weighted images. This lesion was hyperintense on T2 weighted sequence, and was homogeneously enhanced after Gadolinium on T1 weighted images. A medullary oedema was noted. A toxoplasmosis treatment was initiated, without corticotherapy. MR imaging performed one month later (D30), while important clinical improvements were seen, pointed out normal thickness of conus medullaris, without enhancement after Gadolinium. Disease lesions in AIDS with focal spinal cord processes are reviewed, and diagnostic work-up is discussed. Spinal cord single lesion, associated or not with brain involvements should be treated as a toxoplasmic infection, with MR imaging follow up. This work up should avoid medullary biopsy, still required in case of treatment failure. Cerebral involvements, with multiples lesions, can mask medullary localisation.

[Stilling Duane syndrome and MRI: 2 preliminary results]. / Syndrome de Stilling Duane et IRM: 2 observations préliminaires.

Dynamic mode magnetic resonance imaging (DMMRI) allows good visualization of the oculomotor muscles and allows their dimensions to be measured both when they contract and when they relax. The accuracy of this method has been checked and the measurements of the cross section of medial and inferior recti and of superior obliques can be considered to be valid. Measurements of length are inaccurate and the other muscles are not perpendicular to the sectional planes generally used in MRI of the head. By means of a fixation scale situated in the tunnel of the machine, the maximum diameter of medial recti in their thickest part was evaluated in two girls affected by a Stilling Duane retraction syndrome of the left eye. Two direction of the gaze were explored: 25 degrees at the right, then 25 degrees at the left, these angles being obtained by the fixation of particular points of the tunnel scale. The measurements have been made on axial sections, then on coronal sections, both medio-orbital and apical. The first finding is that the diseased medial rectus is much bigger than the healthy one. When relaxed, its thickness is about the same as that of the contracted normal muscle. Coronal orbital cross sections clearly show recession of the belly of the diseased muscle towards the back of the orbit. When contracted it stays in the apical plane and when relaxed in the medio-orbital plane. Lastly the relaxation is much weaker for the pathological muscle than for the healthy one.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural, hemispheric theory of eye, movements and its confirmation by dynamic orbital magnetic resonance imaging.

Two models of eye-movements are in competition with each other: the cardanic suspension (Listing law 1845) and the socket-joint (structural-hemispheric theory 1986). The dynamic orbital MRI demonstrates arguments for the latter which is based upon anatomy and physiology.

[The dynamic study of the human body using MRI]. / Contribution à l'étude dynamique du corps humain par I.R.M.

This work deals with dynamic anatomy of human body explored by magnetic resonance imaging (MRI). Recent development of MRI pulse sequences allow very fast data acquisition. Using an 1,5 Tesla system (General Electric--CGR, Signa), different body segments have been explored, in two different ways. The first approach consisted in a cinematographic display of anatomical sections of an articulation obtained in different positions. The result shows the movement of the articulation. The second approach consisted in the examination of a single slice several times, with cardiac synchronization ("gating"). the result is the evaluation of phase desynchronization, measuring the flow directions and the velocity of circulating fluids. The results are shown as a video tape with commentary. It starts with the joints: the ankle, the knee, the wrist, the hand, the cervical spine, de cervico-occipital junction, the temporo protrusion during deglutition and the ocular movements (normal and pathological), according to different planes, are successively proposed. Finally, flow kinetics are shown: cardiac movements and supra-aortic arterial flow, the intracranial cerebro-spinal fluid circulation, in normal and pathologic (intra-cranial hypertension) cases. The exposition is concluded by showing a work in progress on urine flow during micturition.

[Eye movements: initial dynamic approach in high resolution magnetic resonance imaging]. / Mouvements oculaires: première approche dynamique en imagerie par résonance magnétique (I.R.M.) de haute résolution.

New MR softwares allow a dynamic display of different fonctionnal anatomical regions. This work is a first attempt to visualize the ocular movements. A video tape constitute the support of our results. Technically, the work is performed on a Signa 1,5 T GE CGR System. During each MR acquisition, the subject is asked to fix his gaze successively on each spot of a scale set inside the bore of the magnet. Twenty four images are performed to show the entire lateral course of the globes. The examination time is about half an hour. The video display show the movements of agonist and antagonist muscles, the eyeballs and the optic nerves displacements, in the axial neuro-ocular plane (NOP). Different clinical applications of this new method are discussed (muscular surgery...).

[Semi-automated quantification of MRI high signals observed in multiple sclerosis]. / Quantification semi-automatisée des zones de haut signal IRM observées dans la sclérose en plaques.

MR T2 Weighted sequences on the brain demonstrate disseminated "high signal zones" (HSZ) in patients with Multiple Sclerosis; these morphological alterations are corresponding to the plaques. From the very beginnings of MR in 1981, everybody recognizes the main importance of this fact. MR appears as the most sensible exploration in patients with M.S. But the signal alteration is not specific; the clinical considerations and the evolution are requested. The aim of this work is to give a reference tool for evolutive evaluation of the disease. A work station with a specially developed software are presented. The HSZ thresholding is partially automatic. The edition of a cerebral mapping is developed. These results are discussed.