[Evaluation of associations between barn characteristics, results of barn climate parameter measurements and health indicators in Swiss veal calf herds]. / Evaluation der Zusammenhänge zwischen Stallmerkmalen, gemessenen Stallklimaparametern und Indikatoren für Tiergesundheit in Schweizer Kälbermastbetrieben.

INTRODUCTION: Easy-to-use digital devices to measure climate parameters that can also be used in calf barns have become available commercially in recent years. Data collected in a prospective cohort study in 43 Swiss veal calf operations were evaluated with regard to validity of measured climate parameters, potential associations of those with barn features, and relationships between values of climate parameters and barn characteristics, respectively, with indicators of calf health. Barn parameters, such as ventilation system, access to an outdoor pen and barn size, were recorded, and temperature, air humidity, ammonia and carbone dioxide concentrations were measured at five different locations in each barn during an average of six farm visits over a year. Furthermore, continuous measurements of temperature and humidity (over a period of 72 hours each) were performed once in summer and once in winter in each farm. Whether barn parameters and measured barn climate values are associated as significant risk factors with indicators of calf health (antimicrobial use, mortality and daily weight gain) was explored with statistical methods. Values outside the optimal range were observed for all parameters measured punctually during farm visits and in all seasons. Values of temperature and humidity outside the optimal range were observed more often by continuous than by punctual measurements. Relevant correlations were observed neither among the barn climate values measured punctually nor among measured barn climate values and number of calves, barn surface, bedded surface and barn volume. High maximal group size and presence of mechanic ventilation were positively associated with high antimicrobial use, and high maximal group size and high number of fattening groups were associated with mortality >3%. Farms in lowland regions and high air volume per calf were positively associated with daily weight gain. None of the measured barn climate parameters was associated with the calf health indicators antimicrobial use, mortality and daily weight gain. Therefore, climate parameter measurements appear inadequate to predict calf health in veal fattening operations. The present results show that these (easily) measured parameters are difficult to interpret and should be considered critically.

INTRODUCTION: Des instruments de mesure digitaux faciles à l'emploi pour les paramètres climatiques, qui peuvent aussi être utilisés dans les étables, sont disponibles depuis quelque temps.Afin d'évaluer la validité des valeurs de paramètres du climat mesurées, d'éventuelles associations de ces mesures avec certaines caractéristiques des étables, et les relations des mesures de paramètres associés au climat, respectivement des spécificités des étables, avec des indicateurs de santé animale, des données récoltées dans le cadre d'une étude prospective dans 43 exploitations d'engraissement de veaux en Suisse ont été analysées. D'une part, différents paramètres des étables (tels que le système d'aération, l'accès à un enclos externe, la surface de l'étable) ont été répertoriés. D'autre part, des mesures ponctuelles de la température, de l'humidité de l'air et des concentrations d'ammoniac et de dioxide de carbone ont été effectuées à cinq endroits de chaque étable lors de visites d'exploitation (en moyenne six par ferme sur une durée d'une année). De plus, des mesures continues de la température et de l'humidité ont été conduites sur 72 heures, une fois en été et une fois en hiver, dans chaque exploitation. À l'aide de méthodes statistiques, on a évalué si les caractéristiques des étables et les valeurs de climat mesurées sont associées en tant que facteurs de risque significatifs avec les indicateurs de santé animale (usage d'antibiotiques, mortalité et gain de poids journalier). Lors des mesures ponctuelles, des valeurs en dehors des domaines optimaux ont été observées pour tous les paramètres mesurés et à chaque saison. Des valeurs en dehors des domaines optimaux pour la température et l'humidité ont été constatées plus souvent par les mesures continues que par les mesures ponctuelles. Aucune corrélation significatrice n'a été observée entre les valeurs des paramètres de climat mesurées ponctuellement ou entre les valeurs des paramètres du climat mesurées et le nombre de veaux présents dans l'étable, la surface totale de l'étable, la surface paillée ou le volume de l'étable. Les groupes comptant beaucoup de veaux et la présence d'une ventilation mécanique étaient associés positivement à un usage élevé d'antibiotiques. Les groupes comprenant beaucoup de veaux et la présence d'un grand nombre de groupes étaient associés avec un taux de mortalité supérieur à 3%. Les exploitations en zone de plaine et le volume d'air par veau étaient associés positivement avec le gain de poids journalier. Aucun des paramètres de climat mesurés ne montrait d'association avec les indicateurs de santé animale (usage des antibiotiques, mortalité et gain de poids journalier). Ils semblent donc être inadéquats pour évaluer la santé des veaux dans des exploitations d'engraissement. Nos résultats montrent que les mesures de paramètres du climat sont difficiles à interpréter et doivent être considérés de manière critique.

Prevalence and antimicrobial resistance of opportunistic pathogens associated with bovine respiratory disease isolated from nasopharyngeal swabs of veal calves in Switzerland.

The composition of the bacterial flora in the calf nasopharynx might influence the risk of bovine respiratory disease (BRD). The aims of the present study were, firstly, to investigate the prevalence of bacteria potentially involved in BRD in the nasopharynx of veal calves and to identify associated risk factors for their presence, and, secondly, to provide data on antimicrobial resistance levels in these bacteria. Deep nasopharyngeal swabs were collected from veal calves on 12 Swiss farms over a period of one year by non-random, but systematic sampling for isolation of Pasteurellaceae and Mycoplasma (M.) bovis and dispar. Associations of potential risk factors with occurrence of these bacteria were tested in multivariable mixed logistic regression analyses, based on information gained from extensive questionnaires completed with the farmers. Antimicrobial susceptibility testing was performed for Pasteurellaceae by broth microdilution method to obtain minimal inhibitory concentrations (MIC). Pasteurellaceae, including Pasteurella (P.) multocida, Mannheimia (M.) haemolytica, Bisgaard Taxon 39 and Histophilus (H.) somni, were almost twice as prevalent as M. bovis and dispar in this study. Continuous stocking was a risk factor for the presence of Pasteurellaceae, especially when calves originated from more than six suppliers. In young calves (≤ 91 days), feeding of California Mastitis Test (CMT) positive milk was an additional risk factor for the presence of Pasteurellaceae whereas transport of calves by farmers and livestock traders (as opposed to transport only by farmers) increased the risk in older calves (> 91 days). Risk factors for the presence of M. bovis/dispar were higher number of calves per drinking nipple in young calves, and no access to an outside pen and feeding of CMT positive milk in older calves, respectively. While further research will have to investigate the observed associations in more detail, this suggests that management can play an important role in the prevalence of nasopharyngeal bacteria with a potential subsequent involvement in BRD. Antimicrobial resistance differed between the three bacterial species tested in this study and was highest to oxytetracycline and spectinomycin in P. multocida, oxytetracycline and penicillin in M. haemolytica, and ampicillin and penicillin in H. somni. Only two European VetCAST breakpoints (for florfenicol in P. multocida and M. haemolytica) have been published to date, matching the MIC distribution of the present isolate populations well, in contrast to certain commonly applied American Clinical and Laboratory Institute interpretive criteria. This highlights the potential for further refinement of clinical breakpoints in veterinary medicine.

Associations between antimicrobial treatment modalities and antimicrobial susceptibility in Pasteurellaceae and E. coli isolated from veal calves under field conditions.

Antimicrobial consumption, with bovine respiratory disease as main indication, is higher in the veal calf industry compared to other livestock production branches. The aim of the present study was to investigate possible associations between antimicrobial drug use and resistance in Pasteurellaceae and indicator Escherichia (E.) coli from veal calves under field conditions in a prospective trial. Over a period of one year, nasopharyngeal and rectal swabs were collected from 2587 animals on 12 and 43 farms, respectively. Antimicrobial susceptibility testing was performed on 346 Mannheimia (M.) haemolytica, 1162 Pasteurella (P.) multocida and 2138 E. coli. Drug use was quantified as treatment incidence for each farm based on the used daily dose methodology (TIUDD), separately for group and individual treatments, and for antimicrobial classes. In multivariable mixed logistic regression analyses, risk factors could be identified for reduced susceptibility to certain antimicrobial classes. Group treatment was generally associated with higher rates of not susceptible (NS) M. haemolytica and P. multocida and non-wildtype (non-WT) E. coli. Individual treatment was associated with less NS and non-WT isolates. Age and entry protocol were important confounders with younger animals showing higher rates of NS and non-WT strains. The present findings suggest that, under field conditions, targeted individual treatment of calves can reduce the development of antimicrobial resistance compared to oral group treatment. For the different microorganisms, risk factors for resistance were partially different. This demonstrates that indicator organisms like E. coli do not necessarily reflect the associations observed in respiratory pathogens.

[Transport of veal calves from birth farms to veal farms and calf management in Swiss dairy farms]. / Transporte von Mastkälbern vom Geburts- auf den Mastbetrieb und Kälbermanagement in Schweizer Geburtsbetrieben.

INTRODUCTION: The calf transports of 34 veal farms were documented over a one-year period in order to describe the transport from dairy to veal farms. Veal farms were visited four to eight times, and general farm management data and information on calf purchase were collected. Thirty-five transports were accompanied and documented in detail by the project team. Whenever possible during the accompanied transports, a questionnaire on calf management prior to purchase (calving location, colostrum feeding, vaccinations, iron and selenium supplementation) was filled in with the manager of the dairy (birth) farm. Unaccompanied transports were recorded using a form completed by the veal farmers and the transporters. Information was collected on the number and origin of the calves, transport duration and distance, and stops on farms and markets. A total of 721 transports from dairy to veal farms (531 transports by veal farmers and 190 by suppliers/livestock traders) were documented in the course of the project. Six veal farmers always collected and transported their own calves, nine received their calves from cattle traders only, and 19 used both systems. Veal farmers transported a median of 2.0 (1-21 calves) and traders 3.0 calves (1-74 calves) per transport. The median number of dairy farms per 10 transported calves was 10.0 (1.2-10 dairy farms per 10 transported calves) for transports performed by veal farmers, and 10.0 (2.5-10 dairy farms per 10 transported calves) by traders. The median transport duration was 20.0 minutes (1-330 minutes) with veal farmers and 45.0 minutes (2-414 minutes) with traders. The median available surface per calf during transport was 2 m2 (0.4-6 m2) in transports by veal farmers and 0.6 m2 (0.4-2.7 m2) in those by traders. No bedding was provided on three transports performed by veal farmers although this is prescribed by law. Intranasal vaccination against respiratory disease was performed in 7% of the 88 birth farms included in the study.

INTRODUCTION: Afin de documenter les transports de veaux des exploitations de naissance aux exploitations d'engraissement, les transports dans 34 fermes d'engraissement ont été documentés pendant un an. Les exploitations d'engraissement ont été visitées quatre à huit fois au cours de cette période et des données générales ont été recueillies sur l'exploitation et sur l'achat des veaux. Trente-cinq transports ont été accompagnés et documentés avec précision par l'équipe du projet. Si possible, un questionnaire sur la gestion des veaux avant la vente (lieu de naissance, apport en colostrum, vaccinations, administration de fer et de sélénium) a été rempli avec les responsables de l'exploitation de naissance lors des transports accompagnés. Les autres transports (non accompagnés) ont été documentés à l'aide d'un formulaire que les agriculteurs ont rempli avec les transporteurs. Des informations ont été recueillies sur le nombre et l'origine des veaux, la durée et la distance de transport, ainsi que les arrêts dans les fermes et les marchés. Au total, 721 transports de l'exploitation de naissance à celle d'engraissement ont pu être documentés au cours du projet (531 transports par les engraisseurs eux-mêmes et 190 par des fournisseurs/marchands de bétail). Sur les 34 engraisseurs, six allaient toujours chercher leurs veaux eux-mêmes, neuf les achetaient toujours à un fournisseur, et 19 faisaient les deux. Les engraisseurs transportaient un médian de 2,0 veaux (1-21 veaux) et les fournisseurs de 3,0 veaux (1-74 veaux) par transport. Le nombre médian d'exploitations de naissance par 10 veaux transportés était 10,0 (1,2 à 10 exploitations par 10 veaux) pour les transports effectués par les engraisseurs et de 10,0 pour ceux effectués par les fournisseurs (2,5 à 10 exploitations par 10 veaux). La durée médiane des transports était de 20,0 minutes (1-330 minutes) pour les engraisseurs et de 45,0 minutes (2-414 minutes) pour les marchands de bétail. Pour les transports accompagnés, la surface médiane par veau était de 2 m2 (0,4 à 6 m2) pour les engraisseurs et de 0,6 m2 (0,4 à 2,7 m2) pour les marchands. Il n'y avait pas de litière sur trois transports d'engraisseurs, bien que cela soit exigé par la loi. Une vaccination intranasale contre les maladies respiratoires était réalisée dans 7% des 88 fermes de naissance pour lesquelles un questionnaire a été rempli.

Effects of management practices, animal transport and barn climate on animal health and antimicrobial use in Swiss veal calf operations.

To assess the effects of transport, management factors and barn climate on calf health, 43 Swiss veal farms (11 large farms fattening ≥100 calves and 32 small farms fattening >20 but <100 calves per year) were monitored in a prospective cohort study over a period of one year. Detailed questionnaires on farm structure, management, housing system and animal health were filled out with the farmers during bimonthly visits, and barn temperature, humidity, ammonia and CO2 concentrations were measured. Temperature and humidity were also measured continuously over 72 h once each in winter and summer. In addition, calf purchase and transport from birth farm to fattening unit were documented by the farmers, and the study team accompanied one transport per farm whenever possible. Antimicrobial treatment incidence was calculated from the used daily dose (TIUDD). Risk factors for mortality, average daily weight gain (ADG) and antimicrobial use, as well as factors related to transport and barn climate measures were evaluated with mixed regression models. The overall mortality rate was 5.1% (6.2% in large herds and 3.1% in small ones). Identified risk factors for mortality >3% included a lower number of calves fattened per year and a good hygiene of the feeder. This surprising result was likely due to the fact that the threshold of 3% mortality was rather exceeded in smaller farms. Furthemore, higher temperature variation (range between maximal and minimal temperature over 3 measurement days) in the calf pen was associated with mortality >3% in the univariable analysis. The overall mean ADG was 1.40 ± 0.16 kg. Calf purchase was significantly associated with decreased ADG. The median overall TIUDD was eight daily doses per calf and year (2.1 in small farms and 26 in large farms, respectively); the main indication for treatment was respiratory disease (81.1%). Risk factors for increased TI were no quarantine upon arrival, access to an outside pen, higher numbers of calves per drinking nipple, mechanical ventilation, vaccination against bovine respiratory disease, and a maximum ammonia value >10 ppm in the calf pen. In addition, a higher number of birth farms and calf purchase from markets were associated with increased TI in the univariable analysis. The identified risk factors associated with increased TI and mortality and with decreased ADG should be addressed in priority in veal calf operations to improve calf health and reduce antimicrobial use.

Assessment of occlusive arterial disease of abdominal aorta and lower extremities arteries: value of multidetector CT angiography using an adaptive acquisition method.

We evaluated 16-detector-row CT in the assessment of occlusive peripheral arterial disease (PAD) of the abdominal aorta and lower extremities using an adaptive method of acquisition to optimise arterial enhancement especially for the distal foot arteries. Thirty-four patients underwent transcatheter angiography (TCA) and CT angiography within 15 days. For each patient, table speed and rotation were selected according to the calculated optimal transit time of contrast material obtained after a single bolus test and two dynamic acquisitions at aorta and popliteal arteries. Analysis included image quality and detection of stenosis equal or greater than 50% on a patient basis and on an arterial segment basis. Sensitivity and specificity of CT were calculated with the TCA considered as the standard of reference. CT was conclusive in all segments with no technical failures even in difficult cases with occluded bypasses and aneurysms. On patient-basis analysis, the overall sensitivity and specificity to detect significant stenosis greater than 50% were both 100%. Segmental analysis shows high values of sensitivity and specificity ranging from 91 to 100% and from 81 to 100%, respectively, including distal pedal arteries. Sixteen-detector-row CT angiography using an adaptive acquisition improves the image quality and provides a reliable non-invasive technique to assess occlusive peripheral arterial disease, including distal foot arteries.

Diagnostic performance of MRI for detection of intestinal fistulas in patients with complicated inflammatory bowel conditions.

The diagnostic performance of magnetic resonance imaging (MRI) for detection of intestinal fistulas, other than perianal, in patients with known complicated inflammatory bowel conditions (CIBC) was investigated. Our study group consisted of 20 patients (12 women, mean age 43 years) with CIBC, including Crohn's disease (n=13), colonic diverticulitis (n=3), colitis after radiotherapy (n=3) and of postoperative origin (n=1). Eleven surgically proven enteral fistulas were known in ten (50%) of these patients, being of enterovesical (n=3), enterocolic (n=2), enteroenteral (n=2), rectovaginal (n=2), rectovaginovesical (n=1) and of entercutaneous (n=1) localisation. The other ten patients (50%), used as the control group, showed MR features of CIBC, although without any fistulous tract. Multiplanar T1- and T2-weighted sequences had been performed, including gadolinium-enhanced acquisition with fat saturation (1.5 T). MR findings were independently blindly and retrospectively reviewed by three radiologists for the presence and etiology of any fistula, as well as visualization and characterization of the fistulous tract. Results were compared with surgical findings (n=16) and clinical evolution (n=4). Interobserver agreement was calculated. Interobserver agreement kappa for fistula detection was 0.71. Overall sensitivity, specificity and accuracy for fistula detection were 78.6%, 75% and 77.2%, respectively. Sensitivity for fistula characterization was 80.6%, with visualization of the fistulous tract in all cases, whereby T1-weighted gadolinium-enhanced fat-saturated images were considered the most useful sequences. Gadolinium-enhanced MRI is a reliable and reproducible tool for detection of enteral fistulas secondary to inflammatory conditions.

CT angiography and perfusion CT in cerebral vasospasm after subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: We investigated the association of multisection CT angiography (MSCTA) and perfusion CT (PCT) for the characterization of vasospasm secondary to aneurysmal subarachnoid hemorrhage. MATERIALS AND METHODS: Among 27 patients with symptomatic cerebrovascular vasospasm investigated by digital subtraction angiography (DSA), 18 underwent both cerebral PCT and MSCTA. For the remaining 9, only PCT or MSCTA could be performed. MSCTA was compared with DSA for the detection and characterization of vasospasm on 286 intracranial arterial segments. PCT maps were visually reviewed for mean transit time, relative cerebral blood flow, and relative cerebral blood volume abnormalities and were qualitatively compared with the corresponding regional vasospasm detected by DSA. RESULTS: Vasospasm was grouped into 2 categories: mild-moderate and severe. The depiction of vasospasm by MSCTA showed the best sensitivity, specificity, and accuracy at the level of the A2 and M2 arterial segments (100% for each), in contrast to the carotid siphon (45%, 100%, and 85% respectively). The characterization of vasospasm severity by MSCTA showed a sensitivity, specificity, and accuracy of 86.8%, 96.8%, and 95.2%, respectively, for mild-moderate vasospasm, and 76.5%, 99.5%, and 97.5%, respectively, for severe vasospasm. The PCT abnormalities were related to severe vasospasm in 9 patients and to mild-to-moderate vasospasm in 2. The sensitivity, specificity, and accuracy of PCT in detecting vasospasm were 90%, 100%, and 92.3%, respectively, for severe vasospasm, and 20%, 100%, and 38.5%, respectively, for mild-moderate vasospasm. CONCLUSION: MSCTA/PCT can assess the location and severity of cerebrovascular vasospasm and its related perfusion abnormalities. It can identify severe vasospasm with risk of delayed ischemia and can thus guide the invasive treatment.

Comparison of CT perfusion and angiography and MRI in selecting stroke patients for acute treatment.

Forty-two stroke patients successively underwent perfusion CT (PCT)/CT angiography (CTA) and MRI examinations within 3 to 9 hours following symptom onset; 14 would have been suitable candidates for reperfusion treatment based on MRI findings. Correlation between PCT/CTA and MRI was excellent for infarct size, cortical involvement, and internal cerebral artery occlusion and substantial for penumbra/infarct ratio. Relying on MRI or PCT/CTA would have led to the same treatment decisions in all cases but one.

Choledocholithiasis: repetitive thick-slab single-shot projection magnetic resonance cholangiopancreaticography versus endoscopic ultrasonography.

This prospective study compares repetitive thick-slab single-shot projection magnetic resonance cholangiopancreatography (MRCP) with endoscopic ultrasonography (EUS) for the detection of choledocholithiasis. Fifty-seven consecutive patients (36 women, mean age 61) referred for suspected choledocholithiasis underwent MRCP, followed by EUS. Each procedure was performed by different operators blinded to the results of the other investigation. MR technique included a turbo spin-echo T2-weighted axial sequence with selective fat saturation (SPIR/TSE, TE=70 ms, TR=1,600 ms), followed by coronal dynamic MRCP. The same thick-slab slice was sequentially acquired 12 times as breath-hold single-shot projection imaging (SSh, TE=900 ms, TE=8,000 ms) centred on the common bile duct (CBD). Two experienced radiologists independently and blindly evaluated MR images for the detection of CBD stones. Their inter-observer agreement kappa was determined. Secondly, the two observers read MR images in consensus again. CBD stones were demonstrated in 18 out of 57 patients (31.6 %) and confirmed by endoscopic retrograde cholangiography (ERCP, n=17) or intraoperative cholangiography (n=1). Clinical follow-up served as the "gold standard" in patients with negative results without following invasive procedure (n=28). Sensitivity, specificity, accuracy, positive and negative predictive value for MRCP resulting from consensus reading were 94.9%, 94.4%, 94.7%, 97.4% and 89.5%, respectively. Corresponding values of EUS were 97.4%, 94.4%, 96.5%, 97.4% and 94.4%. Inter-observer agreement kappa was 0.81. Repetitive thick-slab single-shot projection MRCP is an accurate non-invasive imaging modality for suspected choledocholithiasis and should be increasingly used to select those patients who require a subsequent therapeutic procedure, namely ERCP.

Transjugular liver biopsy: prospective evaluation of the angle formed between the hepatic veins and the vena cava main axis and modification of a semi-automated biopsy device in cases of an unfavorable angle.

In cases of transjugular liver biopsies, the venous angle formed between the chosen hepatic vein and the vena cava main axis in a frontal plane can be large, leading to technical difficulties. In a prospective study including 139 consecutive patients who underwent transjugular liver biopsy using the Quick-Core biopsy set, the mean venous angle was equal to 49.6 degrees. For 21.1% of the patients, two attempts at hepatic venous catheterization failed because the venous angle was too large, with a mean of 69.7 degrees. In all of these patients, manual reshaping of the distal curvature of the stiffening metallic cannula, by forming a new mean angle equal to 48 degrees , allowed successful completion of the procedure in less than 10 min.

How to set up and apply reference levels in fluoroscopy at a national level.

A nationwide survey was launched to investigate the use of fluoroscopy and establish national reference levels (RL) for dose-intensive procedures. The 2-year investigation covered five radiology and nine cardiology departments in public hospitals and private clinics, and focused on 12 examination types: 6 diagnostic and 6 interventional. A total of 1,000 examinations was registered. Information including the fluoroscopy time (T), the number of frames (N) and the dose-area product (DAP) was provided. The data set was used to establish the distributions of T, N and the DAP and the associated RL values. The examinations were pooled to improve the statistics. A wide variation in dose and image quality in fixed geometry was observed. As an example, the skin dose rate for abdominal examinations varied in the range of 10 to 45 mGy/min for comparable image quality. A wide variability was found for several types of examinations, mainly complex ones. DAP RLs of 210, 125, 80, 240, 440 and 110 Gy cm2 were established for lower limb and iliac angiography, cerebral angiography, coronary angiography, biliary drainage and stenting, cerebral embolization and PTCA, respectively. The RL values established are compared to the data published in the literature.

[CT-enteroclysis]. / CT-entéroclyse.

Computed tomography enteroclysis (CTE) has become a well-defined imaging modality for the evaluation of various small bowel disorders. The large volume (2 l) of enteral contrast agent administrated via a nasojejunal catheter ensures small bowel distension. Following helical CT acquisition is completed by multiplanar views. CTE is of particular value in intermediate or advanced Crohn's disease. It has become the method of choice for small bowel tumours. The cause and degree of low-grade small bowel obstruction is more readily analyzed with the technique of CTE than conventional CT. CTE should be selectively used to answer specific questions of the small bowel. It essentially contributes to the diagnostic quality of modern small bowel imaging, and therefore deserves an established, well-defined place among the other available techniques.

[Percutaneous sacroplasty]. / La sacroplastie percutanée.

Sacral insufficiency fracture is a debilitating injury for which no active treatment is currently available. It frequently causes significant pain and limits activities of daily living in patients with osteoporosis. Percutaneous vertebroplasty is a common procedure to alleviate the pain associated with thoracic and lumbar vertebral compression fractures. The sacral percutaneous cimentoplasty procedure (sacroplasty) has recently been introduced as an alternative to medical management of osteoporotic sacral insufficiency fractures. The purpose of this article is to illustrate the effectiveness and the utility of percutaneous sacroplasty in this kind of pathology and to show how this procedure can provide symptom relief without having major complications.

[Patient dose optimization in pediatric computerized tomography]. / Optimisation des doses en tomographie computérisée pédiatrique.

The development of CT applications might become a public health problem if no effort is made on the justification and the optimisation of the examinations. This paper presents some hints to assure that the risk-benefit compromise remains in favour of the patient, especially when one deals with the examinations of young patients. In this context a particular attention has to be made on the justification of the examination. When performing the acquisition one needs to optimise the extension of the volume investigated together with the number of acquisition sequences used. Finally, the use of automatic exposure systems, now available on all the units, and the use of the Diagnostic Reference Levels (DRL) should allow help radiologists to control the exposure of their patients.

[CT utilisation in Switzerland: frequency and secular trends]. / Pratique du scanner en Suisse: fréquence et évolution temporelle.

PURPOSE: This study analyzes CT examinations in Switzerland. MATERIALS AND METHODS: Using different sources (administrative data on the equipment, a 1998 nationwide inquiry into practices, and data provided by the Swiss University Hospitals of Basel, Zurich, and Lausanne), we determined the frequency of CT examinations (hospitals and private radiologists) in 1998 according to different descriptive variables and studied the progression in CT use over time. RESULTS: CT scanners increased by 7% between 1998 and 2004. The average annual number of CT examinations in 1998 was 46.3/1000 population, 3.4% of all radiological examinations in Switzerland in 1997-1998. The most frequent examination was CT of the skull (24%), while private radiology institutes perform more CTs of the spine. More CT examinations were performed for men than for women (sex ratio M/F=1.17). The average annual increase in CT in Swiss hospitals varied from 8% for Basel to 18% for Lausanne. Finally, the proportion of pediatric examinations was 5%; their numbers appear to be stabilizing. CONCLUSION: There is a significant increase in CT examinations. It is hoped that our study will heighten awareness among doctors of CT examinations in order to optimize their use.

Cerebral vascular autoregulation assessed by perfusion-CT in severe head trauma patients.

PURPOSE: To use perfusion-CT technique in order to characterize cerebral vascular autoregulation in a population of severe head trauma patients with features of cerebral edema either on the admission or on the follow-up conventional noncontrast cerebral CT. MATERIAL AND METHODS: A total of 80 perfusion-CT examinations were obtained in 42 severe head trauma patients with features of cerebral edema on conventional noncontrast cerebral CT, either on admission or during follow-up. Perfusion-CT results, i.e. the regional cerebral blood volume (rCBV) and flow (rCBF), were correlated with the mean arterial pressure (MAP) measured during each perfusion-CT examination. Ratios were defined to integrate the concept of cerebral vascular autoregulation, and cluster analysis performed, which allowed identification of different subgroups of patients. MAP values and perfusion-CT results in these groups were compared using Kruskal-Wallis and Wilcoxon (Mann-Whitney) tests. Moreover, the functional outcome of the 42 patients was evaluated 3 months after trauma on the basis of the Glasgow Outcome Scale (GOS) score and similarly compared between groups. RESULTS: Three main groups of patients were identified: 1) 22 perfusion-CT examinations were collected in 13 patients, characterized by high rCBV and rCBF values and by significant dependence of perfusion-CT rCBV and rCBF results on MAP values (p<0.001), 2) 23 perfusion-CT examinations collected in 19 patients showing perfusion-CT results similar to control trauma subjects, and 3) 33 perfusion-CT collected in 16 patients, with low rCBV and rCBF values and near-independence of perfusion-CT results with respect to MAP values. The first group was interpreted as showing impaired cerebral vascular autoregulation, which was preserved in the third group. The second group was associated with the best functional outcome; it was linked to the first group, because eight patients went from one group to the other from admission to follow-up. CONCLUSION: Perfusion-CT in severe head trauma patients was able to provide direct and quantitative assessment of cerebral vascular autoregulation with a single measurement. It could hence be used as a guide for brain edema therapy, as well as to monitor the treatment efficiency.

[Undifferentiated sarcoma of the liver: a rare tumor of childhood]. / Le sarcome indifférencié du foie: une tumeur rare chez l'enfant.

UNLABELLED: Undifferentiated sarcoma of the liver is a rare primary tumor of childhood: only about 150 cases have been reported in the literature. CASE-REPORT: A 10 year-old girl was admitted because of diarrhea and weight loss. Sonography, then CT-scan and MRI showed a large tumor of the liver. COMMENTS: In the differential diagnosis of primary liver tumors in children, one should think about undifferentiated sarcoma of the liver, especially if imaging shows haemorrhagic foci and if sonography and CT/MRI display a discordant appearance. Survival has improved in the last decade due to agressive surgery and intensive chemotherapy.

SAPHO syndrome masquerading as metastatic bone disease.

A 46-year-old woman who had had a right mastectomy for breast carcinoma a month before underwent bone scintigraphy. The examination revealed multiple pelvic, vertebral and sternal hot spots suggestive of bone metastases. Standard X-rays and CT confirmed the presence of bony lesions but they were not typical of bone metastases. As the radiographic appearance was reminiscent of SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, osteitis), bone biopsies were performed. Histology showed fibrosis and hyperostosis but no tumour cells. On further questioning, the patient revealed she had had palmar pustulosis and sacroiliitis some years earlier. The purpose of the case report is to show that accurate diagnosis of SAPHO syndrome requires careful clinical and radiological examinations.

[Percutaneous vertebroplasty]. / Vertébroplastie par voie percutanée.

Although vertebroplasty was initially a treatment of vertebral haemangioma or metastases, this procedure is now frequent option to the treatment of osteoporotic vertebral fractures. In this review article, we will discuss the indication, the techniques and the follow-up of the vertebroplasty. This is a risky procedure, which should be performed by experimented physicians working with high-resolution fluoroscopic equipments, by biplane fluoroscopy, to reduce the risk and irradiation to the patient. According to the available follow-up studies, there is clear evidence of a strong improvement of quality of life after vertebroplasty by rapid decreasing of back pain at least during the first six months. Other new studies will analyze the long-term follow-up after vertebroplasty.