We report on a measurement of hard photons (Eg>30 MeV) in the reaction Ar+Ca at 180A MeV at an energy in which photons from the decay of pi0 mesons are dominating. Simultaneous measurement with the ...TAPS spectrometer of the photon spectrum and photon-photon coincidences used for the identification of pi0 enabled the subtraction of pi0 contribution. The resulting photon spectrum exhibits an exponential shape with an inverse slope of E0=(53+-0.03(stat)-5+8(syst)) MeV. The photon multiplicity, equal to (1.21+-0.03(stat)+0.3-0.2(syst))10E0-2, is roughly one order of magnitude larger than the value extrapolated from existing systematics. This enhancement of the hard photon production is attributed to a strong increase in the contribution of secondary np collisions to the total photon yield. We conclude that, on average, the number of np collisions which contribute to the hard photon production is 7 times larger than the number of first chance np collisions in the reaction Ar+Ca at 180A MeV.
The purpose of the study is to compare mammography and magnetic resonance (MR) mammography in detection and assessment of extent, of histologically proven ductal carcinoma in situ (DCIS) and to ...compare MR features of DCIS, with features of invasive carcinoma. Forty histopathologically proven and MR detected pure DCIS lesions were described and compared with 213 enhancing invasive carcinomas. Histopathological examination revealed 49 pure DCIS, MR detected 40 of them (81.6%). There was a good correlation between diameter measured on mammography, MR and histopathology. MR was able to detect additional foci. Ductal enhancement, a focal area or a mass were perceived in respectively 8 (20%), 8 (20%) and 24 (60%) DCIS and in 0, 6 (2.8%) and 207 (97.2%) invasive lesions. Maximal contrast enhancement after 3 minutes was seen in 60.9% of DCIS and before 3 minutes in 61% of invasive masses. Signal intensity increase of more than 100% was seen in 76.9% of DCIS and in 91.1% of invasive carcinomas. DCIS had a wash out in 53.8% and invasive carcinomas in 65.3%. MR was able to detect 81.6% of DCIS. Diameter prediction was good on mammography and MR mammography. The only MR feature exclusively seen in DCIS was ductal enhancement.
Semilobar holoprosencephaly diagnosed by MRI Mortelmans, E S; Van Goethem, J W; van den Hauwe, L ...
JBR-BTR : organe de la Societe royale belge de radiologie (SRBR) = orgaan van de Koninklijke Belgische Vereniging voor Radiologie (KBVR),
2002 Jun-Jul, Letnik:
85, Številka:
3
Journal Article
Breast fibrocystic disease De Roeck, F; Vanderheyden, J; Van Mieghem, F ...
JBR-BTR : organe de la Societe royale belge de radiologie (SRBR) = orgaan van de Koninklijke Belgische Vereniging voor Radiologie (KBVR)
82, Številka:
3
Journal Article
To examine the frequency of community acquired bacteraemia in children in Kigali, Rwanda, blood cultures were obtained from 900 consecutive febrile children (T degrees greater than or equal to 39 ...degrees C) seen at an outpatient clinic over the course of a year. A pathogen was isolated from 112 children (12.4%): Salmonella typhi from 47, S enteritidis from 23, S typhimurium from 13, Streptococcus pneumoniae from 14, Staphylococcus aureus from 9, and Haemophilus influenzae from 3. Salmonella species represented 74% of the isolates. The children with S typhi bacteraemia were older (mean age 75 months) than those with bacteraemia due to other organisms. Controls consisted of febrile, nonbacteraemic children without (group I) or with (group II) Plasmodium falciparum parasitaemia. Bacteraemic children were older and presented more frequently with diarrhoea, vomiting, and dehydration, but less frequently with convulsions than controls. The rate of hospital admission was higher among bacteraemic children (61%) than among group I (39%) or group II (46%) controls. The case-fatality rate was similar in the three groups (9.3% versus 2.9% and 7.3%). Community-acquired bacteraemia in Rwandese children is common and is mainly caused by Salmonella species.
Maxillo-facial trauma Ghysen, D; Ozsarlak, O; van den Hauwe, L ...
JBR-BTR : organe de la Societe royale belge de radiologie (SRBR) = orgaan van de Koninklijke Belgische Vereniging voor Radiologie (KBVR)
83, Številka:
4
Journal Article
Injuries to the facial bones, orbits and adjacent soft tissue structures are common. Despite the increasing safety precautions in modern cars, facial injury is very often caused by motor vehicle ...accidents. Severe trauma to the face is a strong indication for radiological investigation. In the patient with maxillo-facial trauma, the radiological exploration of should answer two major questions: do the fractures involve areas that may alter the physiologic function of the sinuses, mouth, nasal vault or orbit?, and will the fracture result in any cosmetically detectable abnormality? The goal of the radiological work-up is to define the number and exact location of the fractures, to determine if there is any depression, elevation, or distraction of the fracture fragments, and to assess concomitant soft tissue complications. In this article, we review the role of clinical evaluation, plain X-rays, computed tomography (CT) and magnetic resonance imaging (MRI). Imaging findings are correlated with anatomic and physiopathologic considerations. We present a practical classification system of facial trauma, with emphasis on trauma of the paranasal sinuses and facial bones (nasal and tripod fractures, Le Fort fractures) and orbits (foreign bodies, soft tissue and orbital wall injuries such as blow-in and blow-out-, lateral wall- and apical fractures). A third part focuses on trauma of the mandible and the temporomandibular joints.
The incidence of low back pain and leg pain related to the spine is very high in the Western population. As a result of conservative treatment failure there are roughly 200,000 lumbar disk operations ...performed annually. Unsuccessful surgical outcome is known as the failed back surgery syndrome (FBSS). FBSS is a complex and poorly understood syndrome, with as many different imaging findings as different possible etiologic mechanisms. Still we believe some imaging aspects deserve special attention. Firstly it is of particular importance to correctly differentiate residual disk herniation from epidural scar tissue since disk herniation can be an indication for repeat intervention. Secondly when residual disk herniation is present, one should keep in mind that it is not necessarily responsible for the patients complaints. Thirdly, late nerve root enhancement should be considered as pathological. Finally one should be aware of the mechanical back stress that may develop as a result of discectomy. One of the consequences can be secondary foraminal stenosis which is probably one of the most common causes of FBSS.
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