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- Ahle, Margareta, 1966-
(författare)
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Necrotising Enterocolitis : epidemiology and imaging
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Necrotising enterocolitis (NEC) is a potentially devastating intestinal inflammation of multifactorial aetiology in premature or otherwise vulnerable neonates. Because of the broad spectrum of presentations, diagnosis and timing of surgical intervention may be challenging, and imaging needs to be an integrated part of management.The first four studies included in this thesis used routinely collected, nationwide register data to describe the incidence of NEC in Sweden 1987‒2009, its variation with time, seasonality, space-time clustering, and associations with maternal, gestational, and perinatal factors, and the risk of intestinal failure in the aftermath of the disease.Early infant survival increased dramatically during the study period. The incidence rate of NEC was 0.34 per 1,000 live births, rising from 0.26 per 1,000 live births in the first six years of the study period to 0.57 in the last five. The incidence rates in the lowest birth weights were 100‒160 times those of the entire birth cohort. Seasonal variation was found, as well as space-time clustering in association with delivery hospitals but not with maternal residential municipalities.Comparing NEC cases with matched controls, some factors, positively associated with NEC, were isoimmunisation, fetal distress, caesarean section, persistent ductus arteriosus, cardiac and gastrointestinal malformations, and chromosomal abnormalities. Negative associations included maternal pre-eclampsia, maternal urinary infection, and premature rupture of the membranes. Intestinal failure occurred in 6% of NEC cases and 0.4% of controls, with the highest incidence towards the end of the study period.The last study investigated current practices and perceptions of imaging in the management of NEC, as reported by involved specialists. There was great consensus on most issues. Areas in need of further study seem mainly related to imaging routines, the use of ultrasound, and indications for surgery.Developing alongside the progress of neonatal care, NEC is a complex, multifactorial disease, with shifting patterns of predisposing and precipitating causes, and potentially serious long-term complications. The findings of seasonal variation, spacetime clustering, and negative associations with antenatal exposure to infectious agents, fit into the growing understanding of the central role of bacteria and immunological processes in normal maturation of the intestinal canal as well as in the pathogenesis of NEC. Imaging in the management of NEC may be developed through future studies combining multiple diagnostic parameters in relation to clinical outcome.
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| 2. |
- Ahle, Margareta, 1966-, et al.
(författare)
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The role of imaging in the management of necrotising enterocolitis : a multispecialist survey and a review of the literature
- 2018
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Ingår i: European Radiology. - : Springer. - 0938-7994 .- 1432-1084. ; 28:9, s. 3621-3631
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTo investigate current practices and perceptions of imaging in necrotising enterocolitis (NEC) according to involved specialists, put them in the context of current literature, and identify needs for further investigation.MethodsTwo hundred two neonatologists, paediatric surgeons, and radiologists answered a web-based questionnaire about imaging in NEC at their hospitals. The results were descriptively analysed, using proportion estimates with 95% confidence intervals.ResultsThere was over 90% agreement on the value of imaging for confirmation of the diagnosis, surveillance, and guidance in decisions on surgery as well as on abdominal radiography as the first-choice modality and the most important radiographic signs. More variation was observed regarding some indications for surgery and the use of some ultrasonographic signs. Fifty-eight per cent stated that ultrasound was used for NEC at their hospital. Examination frequency, often once daily or more but with considerable variations, and projections used in AR were usually decided individually rather than according to fixed schedules. Predicting the need of surgery was regarded more important than formal staging.ConclusionDespite great agreement on the purposes of imaging in NEC and the most important radiographic signs of the disease, there was considerable diversity in routines, especially regarding examination frequency and the use of ultrasound. Apart from continuing validation of ultrasound, important objectives for future studies include definition of the supplementary roles of both imaging modalities in relation to other diagnostic parameters and evaluation of various imaging routines in relation to timing of surgery, complications, and mortality rate.
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| 3. |
- Ahle, Margareta, 1966-, et al.
(författare)
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The significance of radiographic and ultrasonographic findings in the management of necrotising enterocolitis - results from a survey
- 2017
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Necrotising Enterocolitis (NEC) remains a potentially devastating emergency in neonates, predominantly the premature. Ever since it was first described in the 60's, imaging has played a great role in definition, staging, and monitoring of the disease. The radiographic image can change before the clinical condition, but typical signs are often transient and may be missing even in severe NEC [1-4]. These circumstances have led to the recommendation of frequent imaging and to the insight that the clinical decisions cannot rely solely on radiological signs [5-7]. Ultrasound (US) as a possibility to enhance sensitivity and diagnostic accuracy was first described in the mid 80's [8, 9] and was included in a diagnostic algorithm suggested by in 1994 [6], but despite great effort to develop and validate the method, its role in the management of NEC has not yet been established [7, 10, 11].Meanwhile, in order to improve interobserver agreement and diagnostic accuracy of AR, the radiographic signs of NEC have also been systematized into the DAAS scale [12]. Imaging, as an adjunct to clinical assessment [11], is crucial in the diagnosis and management of NEC. The purpose of this survey was to investigate current views and routines, as described by involved specialists, and identify areas in need of further study and discussion.
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| 4. |
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| 5. |
- Bradley, William G, et al.
(författare)
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Globalization of P4 Medicine: Predictive, Personalized, Preemptive, and Participatory-Summary of the Proceedings of the Eighth International Symposium of the International Society for Strategic Studies in Radiology, August 27-29, 2009
- 2011
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Ingår i: RADIOLOGY. - : Radiological Society of North America. - 0033-8419 .- 1527-1315. ; 258:2, s. 571-582
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Tidskriftsartikel (refereegranskat)abstract
- In August 2009, the International Society for Strategic Studies in Radiology held its eighth biennial meeting. The program focused on the globalization of predictive medicine-or P4 medicine-as it relates to the practice of radiology and radiology research. P4 medicine refers to predictive, personalized, preemptive, and participatory medicine and was the inspiration of Elias Zerhouni, MD, former director of the National Institutes of Health. This article is a summary of some of the key concepts presented at the meeting by an international group of radiologists, imaging scientists, and leaders of industry. In predictive medicine, imaging and imaging-related technologies will likely play an increasing role in the early detection of disease and, thus, the preemption of the development of advanced, hard-to-treat disease. Research into systems biology and molecular imaging promises to personalize medicine, facilitating the provision of the right care to the right patient at the right time. In participatory medicine, increasing interactions with referring physicians and patients will be helpful in raising awareness and recognition of the role of radiologists and will have a positive effect on professionalism. There is also a need to increase awareness of the vital role of radiologists as imaging and radiation safety experts who evaluate the necessity and appropriateness of examinations, monitor performance quality, and are available for postexamination consultations.
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| 6. |
- Brismar, T. B., et al.
(författare)
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GLUCOCORTICOIDS AND SARCOIDOSIS: A LONGITUDINAL STUDY ON THE EFFECTS ON CORTICAL AND TRABECULAR BONE
- 2015
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Ingår i: Sarcoidosis Vasculitis and Diffuse Lung Diseases. - : MATTIOLI 1885. - 1124-0490. ; 32:1, s. 63-69
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Tidskriftsartikel (refereegranskat)abstract
- Background: Glucocorticoid induced osteoporosis is a well-known side effect of glucocorticoid treatment. In sarcoidosis the impact on bone by glucocorticoid treatment is complex due to hormonal disturbances of calcium and vitamin-D, which by itself may cause bone loss. In this study we aimed to investigate the longitudinal impact of glucocorticoids on cortical and trabecular bone in patients with mild, recently diagnosed sarcoidosis.Methods: Ten patients (8 females; mean age 44 (+/- 13)) were studied during one year of glucocorticoid treatment. The assessment of mainly cortical to purely trabecular bone was made by dual X-ray absorptiometry (DXA) of the spine and hip, quantitative ultrasound of the calcaneus, and magnetic resonance relaxometry of the spine and calcaneus. Bone and hormonal measurements were performed at baseline, after 3, 6, and 12 months, and baseline, 3 weeks and 3 months, respectively.Results: DXA of the spine, decreased from baseline at 6 months (P=0.01). R2 of the calcaneus decreased with time (B: -3.6; P=0.03). In the females (n=8) there was a significant decrease in DXA of the spine when comparing 3 months and 6 months (P=0.03), and 3 months and 12 months (P=0.02) and a decrease in R2 of the calcaneus from baseline to 12 months (P=0.01). There was no change in hormonal levels.Conclusion: Treatment of initial mild sarcoidosis with dose tapered glucocorticoid therapy only mildly affects the final trabecular and cortical bone and hormone levels. Dose tapering is an important part in glucocorticoid therapy, likely contributing to the mild effects on bone observed in this study.
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| 7. |
- Flink Elmfors, Anton, et al.
(författare)
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Normal values of the resistivity index of the pericallosal artery with and without compression of the anterior fontanelle
- 2018
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Ingår i: Pediatric Radiology. - : SPRINGER. - 0301-0449 .- 1432-1998. ; 49:5, s. 646-651
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundResistivity index (RI) of the pericallosal artery as is commonly measured during head ultrasound (US) examination in neonates. Some studies have shown that RI measured with gentle compression of the fontanelle provides additional information in cases of neonatal brain anomalies.ObjectiveThe purpose of this study was to establish normal RI values with and without compression in a large population of neonates with normal cranial ultrasound as a function of gestational age.Materials and methodsThe authors of this retrospective study reviewed the RI of 323 infants with normal gray-scale cranial US and with a gestational age ranging 26-42weeks. We conducted the exams both with and without compression of the anterior fontanelle and we studied changes in RI depending on gestational age, gender and type of delivery.ResultsInfants with a gestational age of more than 35weeks tended to have a lower RI (P=0.011). The compression of the anterior fontanelle emphasized the change in RI with increasing gestational age, with higher gestational ages having a lower RI (Pamp;lt;0.001). The results concerning the percentage change between baseline RI and RI with compression showed that infants with higher gestational ages have a smaller percentage change in RI (P=0.002).ConclusionWe established the normal values for RI from 26weeks to 42weeks of gestation. The results of the study show the importance of taking the gestational age into consideration when evaluating the RI.
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| 8. |
- Geijer, Håkan
(författare)
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Radiation dose and image quality in diagnostic radiology : optimization of the dose - image quality relationship with clinical experience from scoliosis radiography, coronary intervention and a flat-panel digital detector
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Det är känt att röntgenstrålning kan orsaka cancersjukdomar, hudskador och andra sidoeffekter. Därför är det viktigt och även föreskrivet i lag att strålexpaneringen inom diagnostisk radiologi skall sänkas så långt som möjligt. Detta kallas på engelska ALARA-principen (As Low As Reasonably Achievable). stråldosen är kopplad till bildkvalitet och denna får inte sänkas så långt att det diagnostiska värdet av en undersökning äventyras. Processen att nå en sådan balans mellan dos och bildkvalitet kallas optimering. Syftet med denna avhandling är att fmna och utvärdera metoder för att optimera förhållandet mellan stråldos och bildkvalitet inom diagnostisk radiologi med fokus på klinisk användbarhet. Arbetet utfördes i tre huvuddelar.Optimering av skoliosröntgen: I första delen utvärderades två nyligen utvecklade metoder får digital skoliosröntgen (digital exponering och pulsad genomlysning). De järnfårdes även med film-skärmsystem som var den tidigare standardmetoden. Stråldosen mättes som Kerma area-produkt (KAP), ytdos (Entrance surface dose, ESD) och effektiv dos; bildkvaliteten värderades med ett kontrast-detaljfantom och genom visuell analys på kliniska bilder. Noggrannheten i vinkelmätningar värderades också. stråldosen för digital exponering var nästan dubbelt så hög som för film med jämförbar bildkvalitet medan pulsad genomlysning hade en mycket låg dos men betydligt sämre bildkvalitet. Variabiliteten i vinkelmätningar var tillräckligt låg i alla metoder. Därefter optimerades inställningarna för digital exponering till en betydligt lägre stråldos med viss sänkning av bildkvaliteten jämfört med utgångsläget.Direktdigital detektor: I den andra delstudien utvärderades en direktdigital detektor med ett kontrast-detaljfantom där stråldosen mättes som ingångsdos i fantomet. Den direktdigitala detektorn gav bättre bildkvalitet vid lägre dos jämfört med både bildplattor och film. Jämförbar bildkvalitet med bildplattor nåddes vid ungefär en tredjedel av dosen.Optimering av perkutan koranar intervention (PCI): I tredje delstudien undersöktes påverkan på stråldos och bildkvalitet av olika inställningar vid kranskärlsröntgen och PCI. Utifrån dessa fynd sänktes dosraten för genomlysning till en tredjedel. Dossänkningen utvärderades i en serie bestående av 154 PCI-procedurer före och 138 efter optimeringen. Genom denna optimering sänktes det totala KAP-värdet signifikant till två tredjedelar av ursprungsvärdet.Sammanfattningsvis påvisar denna avhandling möjligheterna till dossänkning i diagnostisk radiologi genom optimering av den radiografiska processen.
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| 9. |
- Gholami, S, et al.
(författare)
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Standardizing resistive indices in healthy pediatric transplant recipients of adult-sized kidneys
- 2010
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Ingår i: Pediatric Transplantation. - Denmark : Wiley-Blackwell Munksgaard. - 1397-3142 .- 1399-3046. ; 14:1, s. 126-131
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Tidskriftsartikel (refereegranskat)abstract
- Small pediatric recipients of an adult-sized kidney have insufficient renal blood flow early after transplantation, with secondary chronic hypoperfusion and irreversible histological damage of the tubulo-interstitial compartment. It is unknown whether this is reflected by renal resistive indices. We measured renal graft resistive indices and volumes of 47 healthy pediatric kidney transplant recipients of an adult-sized kidney in a prospective study for six months post-transplant. A total of 205 measurements were performed. The smallest recipients (BSA /= 1.5 m(2) (p < 0.0001). Resistive indices increased during the first six months in the smallest recipients (p = 0.02), but not in the two larger recipient groups (BSA 0.75-1.5 m(2) and >/=1.5 m(2)). All three BSA groups showed a reduction in renal volume after transplantation, with the greatest reduction occurring in the smallest recipients. In conclusion, renal transplant resistive indices reflect pediatric recipient BSA dependency. The higher resistance to intra-renal vascular flow and significant decrease in renal volume in the smallest group likely reflect accommodation of the size discrepant transplanted adult-sized kidney to the smaller pediatric recipient vasculature with associated lower renal artery flow.
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