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Biomedical subjects

M Andersson

Publications and source records attributed to M Andersson.

At least 19 recordsLinked to original sources

Monoclonal antibody against T-cell receptor alphabeta induces self-tolerance in chronic experimental autoimmune encephalomyelitis.

The therapeutic effect of monoclonal antibody (H57-597 MoAb) against T-cell receptor (TCR) alphabeta has been investigated on MOG(35-55)-induced experimental autoimmune encephalomyelitis (EAE), as a model system for T-cell-mediated chronic inflammation in the central nervous system (CNS). Short-term administration of the anti-TCR alphabeta immediately after immunization protected the mice from EAE. Furthermore, anti-TCR alphabeta treatment on an established disease restored the self-tolerance which led to a complete remission of EAE and a dramatic reduction of inflammatory cells in the CNS, while treatment with control antibody (hamster IgG) was ineffective. The remission was durable and not associated with disappearance of autoreactive T cells as measured by persistence of MOG-reactive T-cell proliferation in vitro. However, MOG-reactive T cells from anti-TCR-treated animals produced significantly lower amounts of inflammatory TNF-alpha and IFN-gamma. In addition, while a transient deletion of CD4(+) and CD8(+) T cells was observed, a population of T cells expressing CD3, NK1.1 and CD69 (NKT cells) were expanding. By transfer of spleen cells from anti-TCR MoAb-treated animals, we could show that the tolerogenic capacity can be transferred to untreated recipients with EAE. The data indicate therapeutic effect of anti-TCR alphabeta MoAb (H57-597), which represents a promising approach in treatment of T-cell-mediated autoimmune diseases.

Animals↗

Expression pattern of JunD after acute or chronic L-DOPA treatment: comparison with deltaFosB.

In this study, we have used 6-hydroxydopamine-lesioned rats to examine changes in striatal junD and fosB/deltafosB expression induced by acute and chronic treatment with L-DOPA (5 and 15 days). Changes at the protein levels were studied using Western immunoblotting while mRNA changes were compared using in situ hybridization histochemistry. We observed a significant increase in the level of deltaFosB proteins after chronic treatment with L-DOPA, an effect that was not observed for JunD proteins. In addition, the upregulation of deltaFosB was already present after an acute treatment but increased upon chronic treatment. By contrast, junD and deltafosB mRNA were both upregulated significantly above control levels after an acute injection of L-DOPA. In conclusion, this study suggests a differential expression pattern of junD and deltafosB in a rat model of L-DOPA-induced dyskinesia. The upregulation of deltaFosB protein, but not JunD, is likely to reflect an increased stability of the deltaFosB proteins without ongoing enhanced transcription of the encoding genes.

Animals↗

Reduced mortality for women with mammography-detected breast cancer in east Denmark and south Sweden.

The 5-year relative survival from breast cancer in Denmark is 10 percentage points lower than in Sweden. This difference has been demonstrated previously as being caused partly by more involved lymph nodes and larger tumours in Denmark. Sweden has had nationwide mammography-screening coverage since 1991, whereas this is still in its infancy in Denmark. In the search for an explanation for the remaining survival difference, patient delay was a likely candidate. This study compared patient delay and mammography-detection between two national regions. Data on patient delay and mammography were obtained from hospital records from 1989 and 1994, and analysed using Cox proportional hazard analysis of death within the first 5 years, with the factors age, country, delay/mammography detection and established patho-anatomic variables. A comparison of patient delay and mammography detection in 1989 and 1994 showed more mammography-detected tumours in south Sweden and more women with long delay in east Denmark. Mammography detection, but not long patient delay, had a significant effect on the death hazard when adjusting for patho-anatomic risk factors. The hazard ratio was not eliminated in 1989, but in 1994, the hazard ratio between east Denmark and south Sweden was reduced from 1.3 to 1.1. In conclusion, patient delay did not appear to have any effect on 5-year survival when adjusting for patho-anatomic factors, but tumour detection by mammography affected survival favourably and partly explained the survival difference between east Denmark and south Sweden.

Adult↗

Fertility of frozen-thawed stallion semen cannot be predicted by the currently used laboratory methods.

The aim of the project was to use current simple and practical laboratory tests and compare results with the foaling rates of mares inseminated with commercially produced frozen semen. In Exp. 1, semen was tested from 27 and in Exp. 2 from 23 stallions; 19 stallions participated in both experiments. The mean number of mares per stallion in both experiments was 37 (min. 7, max. 121). Sperm morphology was assessed and bacterial culture performed once per stallion. In Exp. 1, progressive motility after 0, 1, 2, 3, and 4 h of incubation using light microscopy, motility characteristics measured with an automatic sperm analyzer, plasma membrane integrity using carboxyfluorescein diacetate/propidium iodide (CFDA/PI) staining and light microscopy, plasma membrane integrity using PI staining and a fluorometer, plasma membrane integrity using a resazurin reduction test, and sperm concentration were evaluated. In Exp. 2, the same tests as in Exp. 1 and a hypo-osmotic swelling test (HOST) using both light microscopy and a fluorometer were performed immediately after thawing and after a 3-h incubation. Statistical analysis was done separately to all stallions and to those having > or = 20 mares; in addition, stallions with foaling rates < 60 or > or = 60% were compared. In Exp. 1, progressive motility for all stallions after a 2-4-h incubation correlated with the foaling rate (correlation coefficients 0.39-0.51), (p < 0.05). In stallions with > 20 mares, the artificial insemination dose showed a correlation coefficient of -0.58 (p < 0.05). In Exp. 2, the HOST immediately after thawing showed a negative correlation with foaling rate (p < 0.05). No single test was consistently reliable for predicting the fertilizing capacity of semen, since the 2 experiments yielded conflicting results, although the same stallions sometimes participated in both. This shows the difficulty of frozen semen quality control in commercially produced stallion semen, and on the other hand, the difficulty of conducting fertility trials in horses.

Animals↗

No signs of immunoactivation in the cerebrospinal fluid during treatment with infliximab.

Neuroinflammatory (demyelinating) disease is a rare but feared complication of treatment with anti-tumour necrosis factor (TNF)alpha in patients with polyarthritis. In this study, blood and cerebrospinal fluid markers of inflammation were analysed in 10 people with polyarthritis before and during treatment with infliximab. An increased systemic expression of interferon (IFN)gamma was detected. Systemic administration of IFNgamma is known to exacerbate multiple sclerosis. However, the present study failed to detect signs of inflammation in the cerebrospinal fluid samples-that is, pleocytosis, oligoclonal immunoglobulin G bands, increased expression of IFNgamma, TNFalpha or interleukin 10, or increased levels of nitric oxide oxidation products. Our initial hypothesis, that the few cases of clinical neuroinflammatory disorders observed during treatment of polyarthritis with anti-TNFalpha represent the extreme end of a commonly occurring minor intrathecal immune activation, which in most cases does not give any overt neurological dysfunction, was not supported. Induction of systemic IFNgamma production may still be relevant in neuroinflammation associated with treatment with anti-TNFalpha.

Adult↗

Inverse relationship between central serotonergic neurotransmission and blood pressure in alcohol-dependent male subjects.

Data has accumulated indicating an inverse relation between central serotonergic (5-HT) neurotransmission and blood pressure in hypertensive rats and in healthy individuals. The present study aimed to elucidate whether an inverse relation exists between systolic (SBP) and diastolic (DBP) blood pressure levels and central 5-HT neurotransmission also in a group of alcohol-dependent individuals. Central 5-HT neurotransmission was assessed by using the maximum prolactin (PRL) responses to the 5-HT probe DL-fenfluramine (DL-FEN; 60 mg po) in 17 alcohol-dependent male subjects investigated during a period of on-going alcohol intake. BP was measured immediately before all time points for blood sampling, and readings before DL-FEN administration were used as the subjects resting BP. Results showed that there were inverse correlations between the maximum PRL responses to DL-FEN and the SBP levels (r = -0.57, p < 0.002) and with the DBP levels (r = -0.52, p < 0.05), respectively. The present study suggests the existence of an association between central 5-HT neurotransmission and blood pressure regulation also in alcohol-dependent individuals.

Adult↗

Incidence and remission of self-reported allergic rhinitis symptoms in adults.

BACKGROUND: A few studies have examined the incidence and remission of allergic rhinitis (AR) in the same general population. METHODS: A questionnaire focused on respiratory symptoms and airway diseases was mailed out in 1992 and in 2000 to the same subjects. Of 4933 subjects, in 1992 aged 20-59 years, 4280 (86.8%) answered at both occasions. AR was defined on self-reported AR and a simultaneous report of nasal symptoms provoked by exposure either to tree-, grass-pollen, furred animals or house dust. Multiple logistic regression adjusted for age and gender was used to analyze potential predictors, reported in 1992, for incidence and remission of AR. RESULTS: The prevalence of AR increased from 12.4% in 1992 to 15.0% in 2000. The incidence of AR from 1992 to 2000 was 4.8%, while 23.1% of the cases with AR in 1992 stated no AR symptoms in 2000 indicating remission. The highest incidence was seen in the youngest age group (20-29 years), whereas remission was highest in the oldest age group (50-59 years). Asthma symptoms during the last year (as reported in 1992) predicted increased incidence of AR and less chance for remission, 1.89 (95%CI 1.08-3.31) and 0.52 (0.31-0.87), respectively. Family histories of AR or asthma predicted increased incidence of AR 1.99 (1.42-2.80) and 1.62 (1.10-2.37), respectively, but were not associated with chance for remission, OR = 1.23 (0.81-1.87) and 0.94 (0.60-1.48). CONCLUSION: This study showed that AR became more common between 1992 and 2000, but also indicated remission in about 20% of the cases within the 8-year period, particularly in older ages. Asthma seems to be associated with higher risk for AR as well as less chance for remission, while heredity of asthma (or AR) may only be associated with the risk for the development and not remission of AR.

Adult↗

Effect of seminal plasma fractions on stallion sperm survival after cooled storage.

This study aimed to evaluate stallion sperm survival after 24 h of cooled storage in the presence of seminal plasma (SP) derived from the sperm-rich fractions (SRF) or sperm-poor fractions(SPF) of the ejaculate, without SP, or in the presence of SP from other stallions. Ejaculates were collected from four stallions using an automated phantom, which separated the semen into five cups. Centrifuged and washed spermatozoa from cup 2 (SRF) were mixed with skim milk extender to a concentration of 100 x 10(6) sperm/ml and then 1:1 (v/v) with SP from the stallion's own or another stallions' second (SP-SRF) or last cup (SP-SPF). Skim milk extender (K) and skim milk extender supplemented with modified Tyrode's medium (KMT) were used as control treatments. After a 24-h storage period in a transport container, spermatozoa were evaluated for motion characteristics and plasma membrane integrity by calcein acetoxymethyl (AM)/propidium iodide staining. The percentage of spermatozoa with intact plasma membranes after storage was lower in SP-SRF than in SP-SPF, and the highest in K (P < 0.05). Progressive motility (PMOT) was lower for sperm stored in SP-SRF than for sperm stored in SP-SPF (P < 0.05), but there was no significant difference in total motility (TMOT). Sperm stored in KMT (P < 0.05) registered the highest TMOT and PMOT percentages. Osmolarity was significantly higher and pH lower in K than in KMT or SP. Treatment with SP-SPF from three stallions benefited the PMOT of sperm from one stallion. These preliminary findings suggest that SP from SRFs may be more harmful during storage than SP from SPFs. Removal of SP improves sperm survival in KMT extender, and exchanging SP between stallions seems to influence sperm survival.

Animals↗

Porcine field fertility with two different insemination doses and the effect of sperm morphology.

In swine artificial insemination, several dose regimens are applied, ranging from 1.5 x 10(9) to 6.0 x 10(9) spermatozoa per intra-cervical insemination dose. A lower sperm dose is more profitable for artificial insemination centres and offers a more effective use of superior boars. To evaluate fertility, 50 boars were used for a total of 10 773 homospermic first inseminations at a dose of 2 billion spermatozoa. In addition, 96 boars were used at a dose of 3 billion spermatozoa for 34 789 homospermic first inseminations. Fertility was determined by a 60-day non-return rate (NR%) of first inseminations. Litter size was registered by total number of piglets born separately in primiparous and multiparous farrowings. On average, a sow was inseminated 1.5 times. A significant decrease was observed in all three fertility parameters (NR%, litter size of both primiparous and multiparous farrowings) with a dose of 2 billion spermatozoa compared with a dose of 3 billion spermatozoa. The NR% was 75.8% and 84.0% (p < 0.001), the mean litter size of primiparous farrowings 10.1 and 10.7 (p < 0.001) and the mean litter size of multiparous farrowings 11.7 and 12.1 (p < 0.001) for 2 and 3 billion spermatozoa/dose, respectively. The proportion of normal spermatozoa in the sperm morphology analysis correlated significantly with NR% in both insemination regimens: p < 0.001, r = 0.604 and p < 0.05, r = 0.223 for 2 and 3 billion spermatozoa/dose, respectively. These results confirm that quantity can at least partly compensate for poor sperm quality. When the boars with <70% normal spermatozoa in the morphology evaluation were excluded from the data there were no correlation between the sperm morphology and NR%. However, the difference between the NR% and litter size remained statistically significant (p < 0.001) in favour for the bigger insemination dose. In conclusion, a decrease in sperm dose from 3 to 2 billion spermatozoa on commercial farms will severely decrease prolificacy at least under field conditions, where a sow is inseminated an average of 1.5 times/heat, and the semen is typically used within 3 days after collection. We recommend that under commercial circumstances the homospermic semen doses contain no <3 billion spermatozoa/dose.

Animals↗

Pregnancy rates in lactating Holstein-Friesian cows after artificial insemination with sexed sperm.

The effects of artificial insemination (AI) using sexed sperm on pregnancy rates have seldom been studied in lactating dairy cows on commercial dairy farms. We evaluated pregnancy results after AI of 306 lactating dairy cows, of which 157 were inseminated with 2x10(6) frozen/thawed sexed sperm and 149 with 15x10(6) frozen/thawed unsexed sperm. The average pregnancy and calving rates were 21.0% and 20% for the sexed-sperm AIs and 46% and 45% for the unseparated control-sperm AIs respectively (p<0.001). The proportion of female calves derived from sexed-sperm AI was 82% compared with 49% for control AI (p<0.01). The proportion of live and healthy calves in single births was 100% for sexed-sperm AI and 97% for control AI (p>0.05). Our results indicate that AI with low-dose sexed sperm under field conditions in commercial dairy herds without oestrus synchronization results in significantly reduced pregnancy rates compared with normal-dose AI. Improved insemination strategies combined with increased sperm doses are needed before the use of sexed sperm can be of any significant benefit for the dairy and beef industry.

Animals↗

Motility and plasma membrane integrity of spermatozoa in fractionated stallion ejaculates after storage.

With the aim of investigating properties of stallion seminal plasma to eventually improve semen-handling techniques, sperm motility and plasma membrane integrity were analysed in different fractions of the ejaculates after storage. Semen was collected using a computer-controlled automated phantom that separates the ejaculates into five successive cups. Samples containing seminal plasma and skim milk extender were compared with samples stored in skim milk extender after the removal of seminal plasma by centrifugation. Fractionated ejaculates were stored cooled for 24 h after dilution with extender (Expt 1) or frozen in liquid nitrogen (Expt 2). In Expt 1, cup 1 was pre-sperm fluid, cups 2 and 3 sperm-rich fractions, and cup 4 sperm-poor fractions. In Expt 2, cups 1 and 2 were sperm-rich fractions, and cups 3 and 4 sperm-poor fractions. One sample (WE) represented the whole ejaculate in both experiments. Motility parameters were determined with a Hamilton-Thorn Motility Analyzer, and plasma membrane integrity was assessed using carboxyfluorescein diacetate and propidium iodide staining and fluorescence microscopy. The removal of seminal plasma lowered motility values, but not plasma membrane integrity, in both experiments. No significant differences between cups were observed after cooled storage. The cups differed significantly in most post-thaw motility parameters, and the sperm-rich fraction showed higher post-thaw motility than the whole ejaculate.

Animals↗

Transplantation of normal boar testicular cells resulted in complete focal spermatogenesis in a boar affected by the immotile short-tail sperm defect.

Transplantation of testicular cells, also known as spermatogonial stem cell transplantation, is a relatively new approach in the field of male infertility. We used this technique to determine whether donor-derived sperm production in unrelated porcine recipients is possible following ultrasound-guided transfer of testicular cells. This study was undertaken because we had a strain of Finnish Yorkshire boars with a hereditary recessive gene defect rendering all spermatozoa immotile and anatomically abnormal in homozygous boars. Thus, monitoring of the focal success of colonization of donor spermatogonia with subsequent production of progressively motile spermatozoa was extremely sensitive. Testicular cells from young normal crossbred boars were transplanted into the testes of two boars affected with the immotile short-tail sperm (ISTS) defect. Prior to the transplantations, busulfan was used to suppress recipients' endogenous spermatogenesis. The ejaculates were collected and analysed for the presence of motile spermatozoa. In one of the two recipient boars transplanted with testicular cells from normal donors, motile spermatozoa appeared in the ejaculates 12 weeks after the transplantation. Spermatozoa manually selected under a microscope from a frozen aliquot of ejaculate collected 27 weeks after transplantation were genotyped. In two of the 20 vials the donor-derived genotype was visible. The genotyping results substantiated the success - as indicated by the appearance of motile spermatozoa after the spermatogonial transfer. Thus, donor-derived sperm production in unrelated recipients is possible. In addition, the production after transplantation of progressively motile spermatozoa with normal tail lengths shows that the ISTS defect in Finnish Yorkshire boars apparently results from defective transcription of an essential gene for sperm motility in germline cells. To conclude, the transplantation of donor testicular cells can, at least in boars with the ISTS defect, result in complete focal spermatogenesis.

Animals↗

Cognitive and motor function in people with multiple sclerosis in Stockholm County.

The aim of this study was to analyse cognitive and motor function in a population-based sample of people with multiple sclerosis (PwMS), taking into account both disease-related data and sociodemographic factors. Data were collected from 166 PwMS during home visits. Cognitive function was assessed by the Mini-Mental State Examination (MMSE), the Free Recall and Recognition of 12 Random Words Test (FRR12RWT), and the Symbol Digit Modalities Test (SDMT); manual dexterity by the Nine-Hole Peg Test (NHPT); global motor capacity by the Lindmark Motor Capacity Assessment; and walking capacity by a timed 10-metre walk. On cognitive tests, 55% (MMSE), 84% (FRR12RWT), and 45% (SDMT) of PwMS scored within the normal range; 27% of PwMS displayed normal manual dexterity, 9% had a maximal motorcapacity score, and 8% walked at normal speed. Factors associated with normal cognitive function were lower disability and higher education; lower disability and current employment were predictive of capacity to perform the NHPT and to walk 10 metres. In conclusion, cognitive function was normal in approximately half of the PwMS investigated, while a minority displayed normal manual dexterity and normal walking capacity. Thus, both disease severity and sociodemographic factors appear to influence cognitive and motor function in MS.

Activities of Daily Living↗

Obstructive airways diseases, smoking and use of inhaled corticosteroids in southern Sweden in 1992 and 2000.

OBJECTIVE: To examine the prevalence of obstructive pulmonary diseases, respiratory symptoms, smoking habits and pulmonary medication in an adult population, and to compare the results with a study performed in the same geographical area in 1992. DESIGN: In 2000, a postal questionnaire was sent to a randomly selected population of 5179 subjects aged 20-59 years living in southern Sweden. RESULTS: The participation rate was 71.3%. Self-reported asthma was reported by 8.5% of all respondents (vs. 5.5% in 1992, P < 0.001) and 14.5% of females aged 20-29 years. Self-reported chronic bronchitis and/or emphysema and/or chronic obstructive pulmonary disease (CBE/COPD) was reported by 3.6% (vs. 4.6% in 1992, non-significant) with the highest prevalence (5.7%) in the 50-59 year cohort. Smoking decreased from 33.3% in 1992 to 28.4% in 2000 (P < 0.05). About 46% of asthmatics reported nocturnal respiratory symptoms, and 69% reported having had asthma symptoms in the last 12 months. Use of inhaled steroids increased in subjects with asthma and CBE/COPD from 19.4% to 36.5% (P < 0.05) and from 8.6% to 30.0% (P < 0.05), respectively. CONCLUSIONS: Self-reported asthma increased significantly between 1992 and 2000, but the prevalence of CBE/COPD was unchanged. The high proportion of reported symptoms in asthmatics despite an increased use of steroids suggests that further efforts are needed to improve asthma treatment.

Administration, Inhalation↗

Size-dependent carbon monoxide adsorption on neutral gold clusters.

We report on experiments probing the reactivity of neutral Au(n) clusters, n = 9-68, with carbon monoxide. The gold clusters are produced in a pulsed laser vaporization cluster source, operated at room temperature (RT) or at liquid-nitrogen temperature (LNT), pass through a low-pressure reaction cell containing CO gas, and are subsequently laser ionized. The reaction probabilities are determined by recording mass abundance spectra with time-of-flight mass spectrometry. The main observations are a strong temperature dependence and a remarkable size dependence. Upon cooling of the cluster source to LNT, the reactivity increases substantially. At LNT, the reaction probabilities for Au(n) with the first CO molecule are about a factor 10 higher than at RT. Moreover, adsorption of two, three, and even four CO molecules is observed, in contrast to RT clusters which at most adsorb one CO molecule. This temperature dependence is related to the lifetime of the cluster-molecule complexes, being much longer for cold clusters. The observed striking size dependence is similar at both temperatures and is discussed in terms of the electronic structure effects.

Journal Article↗

Fecundability according to male serum inhibin B--a prospective study among first pregnancy planners.

BACKGROUND: New biological markers of male fecundity are needed for use in large-scale epidemiological studies. We studied the association between male inhibin B and fecundability. METHODS: Four hundred and thirty Danish couples without previous reproductive experience were followed from termination of contraception until pregnancy or for a maximum of six menstrual cycles. At enrolment we obtained semen samples (n = 418) and blood samples to measure reproductive hormones, including inhibin B (n = 343). RESULTS: The fecundability odds ratio for an increment of male inhibin B by 1 log pg/ml was 1.428 (95% confidence interval 1.022-1.994), adjusted for factors influencing the crude estimate. Only inhibin B values below 100 pg/ml were strongly related to fecundability. We designed a receiver operating characteristic curve based on the 29 males with serum inhibin B #100 pg/ml. The area under the curve (AUC) for inhibin B was 0.787 and the corresponding AUCs for sperm density and FSH were 0.913 and 0.800, respectively. CONCLUSION: Serum inhibin B may be a reliable marker of male fecundity for epidemiological research and may have some advantages over sperm density. Our findings do not support the replacement of sperm density by male inhibin B when obtaining sperm data is an option.

Adult↗

Normal values and differences between intraperitoneal and subcutaneous microdialysis in patients after non-complicated gastrointestinal surgery.

OBJECTIVE: Visceral ischemia is an early event in the development of shock and organ failure. Microdialysis has been presented as a promising method for detection of visceral hypoxia and ischemia. The aim of this study was to investigate differences in the metabolic response measured by microdialysis between intraperitoneal and subcutaneous locations and to estimate normal values of lactate/pyruvate ratio, glucose and glycerol. MATERIAL AND METHODS: Intraperitoneal and subcutaneous metabolic responses were compared regarding lacate/pyruvate ratio, glucose and glycerol, during 45 postoperative hours in 33 patients undergoing various non-complicated elective major gastrointestinal surgery. RESULTS: Intraperitoneal lactate/pyruvate ratio started around 15 and decreased over time, while subcutaneous levels were stable around 9. Glucose levels were higher intraperitoneally and increased rapidly during the first 9 h to 8.6 mM, while the subcutaneous levels increased during 21 h to 7.5 mM. Intraperitoneal glycerol levels were stable around 100 microM, while subcutaneous values started around 230 microM and then increased. CONCLUSIONS: In a non-complicated postoperative course the lactate/pyruvate ratio and glucose levels are higher intraperitoneally, suggesting a higher postoperative intraperitoneal metabolism. Glycerol levels are higher and increase subcutaneously, suggesting increased postoperative energy demand, particularly in the visceral organs, as being responsible for the lipolysis seen in the subcutaneous tissue.

Adult↗

MRI combined with MR cholangiopancreatography versus helical CT in the evaluation of patients with suspected periampullary tumors: a prospective comparative study.

PURPOSE: To establish the diagnostic accuracy of MRI including MR cholangiopancreatography (MRCP) compared with helical CT in the differentiation of malignant and benign lesions in the periampullary region. MATERIAL AND METHODS: Fifty-one patients (27 M, 24 F, mean age 66 years, range 39-86 years) with obstructive jaundice and sonographic evidence of intra- and extrahepatic bile duct dilatation (n=31) or suspicion of periampullary tumor, based on previously performed ultrasound and/or CT examination (n=20), were studied. MRI with MRCP and helical CT were reviewed blindly under standardized conditions. Lesion status (differentiation of malignant versus benign) was rated on a 5-point diagnostic confidence scale. Reference standards for comparison were findings at surgery or laparoscopy and/ or the clinical outcome. The predictive value of imaging findings was determined with multivariate logistic regression analysis. RESULTS: The areas under the receiver operating characteristic curve were 0.96 for MRI with MRCP and 0.81 for CT (P <0.05). Multivariate analysis of eight imaging variables at MRI indicated that a stricture with malignant characteristics at MRCP was the best predictor of malignancy. CONCLUSION: MRI with MRCP was significantly more accurate than CT in differentiating between malignant and benign lesions in patients with suspected periampullary tumors, mainly due to the information obtained on the MRCP images of the biliary and pancreatic duct anatomy.

Adult↗