Percentiles of intrauterine placental volume and placental volume relative to fetal volume: A prospective magnetic resonance imaging study.

INTRODUCTION: We aimed to provide percentiles of intrauterine placental growth and placental growth relative to fetal growth (placental to fetal ratio) by measuring placental and fetal volumes by magnetic resonance imaging (MRI). METHODS: In this prospective study, 107 unselected singleton pregnancies were examined by MRI at gestational week 27 and 37. Based on the estimated volumes of the placenta and the fetus, we calculated median and percentiles at gestational weeks 27 and 37. RESULTS: Median placental volume at gestational week 27 was 513 cm3 (Inter Quartile Range (IQR) 182 cm3), and 831 cm3 (IQR 252 cm3) at week 37. The 10th - 90th percentiles included placental volumes between 392 and 717 cm3 at gestational week 27, and 631-1087 cm3 at week 37. The placental to fetal ratio was significantly higher at gestational week 27 than at week 37, with a median ratio of 0.54 (IQR 0.18) and 0.31 (IQR 0.08), respectively (p < 0.001). The 10th-90th percentiles included placental to fetal ratios between 0.43 and 0.73 at gestational week 27 and 0.25-0.39 at week 37. DISCUSSION: At gestational week 27, the placental volume was about half the size of the fetal volume, whereas at week 37, the placental volume was about one third of the fetal volume. This finding suggests that placental growth was less prominent than fetal growth after gestational week 27. Knowledge about the distribution of intrauterine placental size in the general population of pregnancies are prerequisites for diagnosing abnormal placental size.

Prevalence of abnormal ECGs in male soccer players decreases with the Seattle criteria, but is still high.

Electrocardiogram (ECG) and echocardiography are mandatory in preparticipation cardiac screening in soccer players. Abnormal ECG findings usually require follow-up investigations. The main aim of this study was to compare the prevalence of abnormal ECG findings in male professional soccer players according to European Society of Cardiology's (ESC) recommendations and the Seattle criteria, and to assess the need for echocardiography. ECGs from 587 of 595 (99%) players were recorded with ClickECG, and measurements were derived with visually adjusted on-screen calipers on the computer-based averaged PQRST complex. Echocardiographic recordings were performed with Vivid 7/i and categorized according to reference values for athlete's heart. After the initial screening, 32 (5.5%) players were recommended for follow-up. The prevalence of abnormal ECGs was 29.3% vs 11.2% according to the ESC's recommendations and the Seattle criteria, respectively. None of the players with abnormal ECGs only according to the ESC's recommendations had abnormal echocardiograms. Echocardiography alone detected one player with abnormalities (athlete's heart). The Seattle criteria reduced the number of athletes with abnormal ECGs considerably compared with the ESC recommendations. Based on echocardiographic evaluations, this increased the specificity of the Seattle criteria, without increasing the number of false-negative ECGs. The need for mandatory echocardiography in soccer players seems limited.

Visual or computer-based measurements: important for interpretation of athletes' ECG.

BACKGROUND: ECG is recommended for preparticipation health examination in athletes. Owing to a lack of consensus on how to read and interpret athletes' ECGs, different criteria for abnormality are used. AIMS: To compare the prevalence of abnormal ECGs and test the correlation between visual and computer-based measurements. METHODS: In a preparticipation cardiac screening examination of 595 male professional soccer players aged 18-38 years, ECGs were categorised according to the European Society of Cardiology's (ESC) recommendations and the Seattle criteria, respectively. Visual measurements were conducted with callipers on-screen on the averaged PQRST complex in each lead, calculated by the trimmed mean. Computer-based measurements were derived from the medium beat. Heart rhythm and conduction were scored visually by a cardiologist. Categorical variables were compared by κ statistics (K) and continuous variables by intraclass correlation. RESULTS: ECGs of good quality were available from 579 players. According to the ESC's recommendations and Seattle criteria, respectively, ECGs were categorised as abnormal in 171 (29.5%) vs 64 (11.1%) players after visual assessment, and in 293 (50.6%; K=0.395) vs 127 (21.9%; K=0.564) after computer-based measurements. Intraclass correlation was very good for measurements of R and S wave amplitudes and moderate to very good for intervals. K was very good for pathological Q wave amplitudes and moderate for T wave inversions. CONCLUSIONS: Abnormal ECGs were more than twice as common after computer-based than after visual measurements. Such a difference will markedly influence the number of athletes who need further examinations. Reference values may need adjustments dependent on measurement methods.

Low-grade systolic murmurs in healthy middle-aged individuals: innocent or clinically significant? A 35-year follow-up study of 2014 Norwegian men.

OBJECTIVE: To determine whether a low-grade systolic murmur, found at heart auscultation, in middle-aged healthy men influences the long-term risk of aortic valve replacement (AVR) and death from cardiovascular disease (CVD). Setting and subjects. During 1972-1975, 2014 apparently healthy men aged 40-59 years underwent an examination programme including case history, clinical examination, blood tests and a symptom-limited exercise ECG test. Heart auscultation was performed under standardized conditions, and murmurs were graded on a scale from I to VI. No men were found to have grade V/VI murmurs. Participants were followed for up to 35 years. RESULTS: A total of 1541 men had no systolic murmur; 441 had low-grade murmurs (grade I/II) and 32 had moderate-grade murmurs (grade III/IV). Men with low-grade murmurs had a 4.7-fold [95% confidence interval (CI) 2.1-11.1] increased age-adjusted risk of AVR, but no increase in risk of CVD death. Men with moderate-grade murmurs had an 89.3-fold (95% CI 39.2-211.2) age-adjusted risk of AVR and a 1.5-fold (95% CI 0.8-2.5) age-adjusted increased risk of CVD death. CONCLUSIONS: Low-grade systolic murmur was detected at heart auscultation in 21.9% of apparently healthy middle-aged men. Men with low-grade murmur had an increased risk of AVR, but no increase in risk of CVD death. Only 1.6% of men had moderate-grade murmur; these men had a very high risk of AVR and a 1.5-fold albeit non-significant increase in risk of CVD death.

Molecular genetic analysis of long QT syndrome in Norway indicating a high prevalence of heterozygous mutation carriers.

Mutations in the KCNQ1, HERG, SCN5A, minK and MiRP1 genes cause long QT syndrome (LQTS), of which there are two forms: the Romano Ward syndrome and the Jervell and Lange-Nielsen syndrome. We have performed DNA sequencing of the LQTS-associated genes in 169 unrelated patients referred for genetic testing with respect to Romano Ward syndrome and in 13 unrelated patients referred for genetic testing with respect to Jervell and Lange-Nielsen syndrome. A total of 37 different mutations in the 5 genes, of which 20 were novel, were identified. Among patients with the most stringent clinical criteria of Romano Ward syndrome, a mutation was identified in 71%. Twelve of the 13 unrelated patients referred for genetic testing with respect to Jervell and Lange-Nielsen syndrome were provided with a molecular genetic diagnosis. Cascade genetic screening of 505 relatives of index patients with molecularly defined LQTS identified 251 mutation carriers. The observed penetrance was 41%. Although caution must be exerted, the prevalence of heterozygotes for mutations in the LQTS-associated genes in Norway could be in the range 1/100-1/300, based on the prevalence of patients with Jervell and Lange-Nielsen syndrome.

Digitalis: a dangerous drug in atrial fibrillation? An analysis of the SPORTIF III and V data.

OBJECTIVE: In heart failure, digitalis increases exercise capacity and reduces morbidity, but has no effect on survival. This raises the suspicion that the inotropic benefits of digitalis may be counteracted by serious adverse effects. Patients with atrial fibrillation (AF) were studied to clarify this. DESIGN: In the Stroke Prevention using an ORal Thrombin Inhibitor in atrial Fibrillation (SPORTIF) III and V studies, 7329 patients with AF at moderate-to-high risk were randomised to preventive treatment of thromboembolism, either with warfarin or the oral direct thrombin inhibitor ximelagatran. The survival of users and non-users of digitalis was investigated. RESULTS: At baseline, 53.4% of the study population used digitalis, and these patients had a higher mortality than non-users (255/3911 (6.5%) vs 141/3418 (4.1%), p<0.001; hazard ratio (HR) = 1.58 (95% CI 1.29 to 1.94)). Digitalis users also had more baseline risk factors. After multivariate risk factor adjustment, the increased mortality persisted (p<0.001; HR = 1.53 (95% CI 1.22 to 1.92 vs 1.23 to 1.92)). CONCLUSIONS: The results suggest that digitalis, like other inotropic drugs, may increase mortality. This may be concealed in heart failure, but be revealed in patients with AF, who need the rate-reducing effect of digitalis, but do not benefit much from an increased inotropy. Cautious interpretation of the data is mandatory since the patients were not randomised with respect to digitalis use.

Magnetic resonance-assisted imaging of slow flow in the pancreatic and common bile duct in healthy volunteers.

BACKGROUND: Magnetic resonance cholangiopancreaticography (MRCP) is commonly used to evaluate the pancreatic (PD) and common bile duct (CBD), and the addition of secretin is used to obtain functional information (S-MRCP). Neither method gives any information on flow velocities within the ducts. PURPOSE: To evaluate a new, MRI diffusion-based, slow-flow-sensitive sequence for the detection of slow flow changes in the PD and CBD. MATERIAL AND METHODS: Seven healthy volunteers were examined. A modified single-shot turbo spin-echo sequence was used to detect slow flow changes. Three b factors (0, 6, and 12 s/mm(2)) were used. The flow sensitivity was applied in two directions, vertically and horizontally. Scanning was performed before and after glucagon was given, and again after an intravenous injection of secretin. The sequence gives signal loss from a duct when flow increases, and such changes were recorded. RESULTS: All images showed the PD with b = 0 (no flow sensitization). After administration of glucagon, artifacts from bowel movements were reduced and visibility of the PD was improved at both b = 6 and b = 12. Significant reduction of the visibility of the PD, indicating increased flow, was recorded both at b = 6 and b = 12 after the administration of secretin. There were no changes in the visibility of the CBD. CONCLUSION: This study shows that MRI-based detection of slow flow changes inside the PD is possible. Due to the sequence's high sensitivity to any motion, further studies are required before adopting the method for clinical use.

Dynamic first pass 3D EPI of the prostate: accuracy in tumor location.

PURPOSE: To evaluate the potential of dynamic contrast enhanced (DCE) 3D EPI in the location of prostate cancer. MATERIAL AND METHODS: A DCE 3D EPI scan was included in the magnetic resonance imaging protocol for prostate examination. Twenty-eight patients who subsequently underwent radical prostatectomy were included in the study. T2-weighted (T2W) Turbo Spin Echo (TSE) images were initially evaluated by two radiologists. Parametric images reflecting contrast enhancement were added and new evaluations performed. The results were compared with histology from resected specimens. Accuracies and interobserver agreements were calculated. RESULTS: Interobserver agreement was Kw =49+/-3% for the T2W technique and Kw=30+/-3% for the combined techniques. No statistically significant advantages were found for location of tumor in the prostate or in the seminal vesicles by adding the DCE information. CONCLUSION: DCE 3D EPI did not improve tumor location compared with that of T2W TSE images. Further investigation is needed on how best to exploit the DCE technique.

A new pulse sequence to visualize slow flow.

The purpose of this paper is to present a new pulse sequence for visualizing slow flow. The new sequence consists of an initial Stejskal-Tanner flow sensitization part followed by a DEFT pulse and a spoiler gradient. A single-shot TSE readout train is then applied to sample the NMR signal. The sequence was initially tested using a simple flow phantom. To verify potential clinical use, both flow-sensitive MRCP and cerebrospinal fluid (CSF) images were produced. The phantom study proved the sequence sensitivity to flow in the range 0-1 cm/s. bVE-factors 1.5, 3, 6 and 12 were chosen. Within this flow velocity range, the signal dropped as predicted theoretically. This indicates that the method can be used to quantify flow. All anatomical features seen in a standard MRCP sequence were identified and the methods sensitivity to CSF flow was demonstrated by sagital images of the head. A new pulse sequence sensitive to slow flow has been developed.

Bowel MR imaging with oral Gastrografin: an experimental study with healthy volunteers.

Our objective was to evaluate Gastrografin for MR bowel imaging. Twenty-three healthy volunteers in two randomised groups received 300 or 400 ml 50% Gastrografin, drunk continuously during 2 and 3 h, respectively. Images were applied during breath-hold in three orthogonal orientations. The balanced fast-field echo (BFFE) and balanced turbo field-echo (BTFE) sequences, with acquisition times from 13 to 25 s, were used before gadolinium (Gd) DTPA implying 1- to 2-mm-thick slices locally or 6-mm-thick slices through the entire gastrointestinal tract. The Gd-enhanced images were performed using a 3D T1-weighted FFE sequence with water selective excitation (Proset). Image quality, including bowel distention, homogeneity of opacification and wall conspicuity, were evaluated by two experienced reviewers, and the adverse reactions were recorded. Very good or excellent distention, homogeneity and wall conspicuity were achieved in the central segments from the ileum to the left colon flexure in 83-96% of cases, due to the adequate contrast media supply in these regions. Distention, homogeneity and delineation were good in the central segments of the remaining bowels. Diarrhoea was a major problem affecting all participants, followed by nausea. Provided that there is modern fast sequential technology, excellent MR imaging of the bowel can be achieved by the oral administration 50% diluted Gastrografin. Further studies are needed to refine the technique and optimise the quantity and concentration of Gastrografin in order to avoid or reduce adverse reactions.

Do cardiac glycosides affect platelet function? A flow cytometric study in healthy volunteers.

OBJECTIVE: Cardiac glycosides exert their inotropic effect by increasing intracellular calcium. Increased intracellular calcium is a key event in platelet aggregation. In aggregometer studies, digitalis has been found to augment platelet agonist responses. A prothrombotic effect of digitalis might be concealed since heart failure and atrial fibrillation per se predispose to thromboembolism. The present study investigates the effects of digitoxin on platelet function in healthy volunteers. METHODS: Twenty healthy, non-smoking volunteers were randomised to receive digitoxin ( n = 10, 0.6 mg day 1, 0.4 mg day 2, then 0.1 mg daily) or placebo ( n = 10) for 10 days. Platelet function was then analysed ex vivo using three-colour whole-blood-flow cytometry, both in non-stimulated mode and after agonist stimulation with 0.1 micromol/l adenosine diphosphate (ADP), 10 micromol/l ADP and 5.0 micromol/l epinephrine (final concentrations). Expression of activated fibrinogen receptor, von Willebrand's factor receptor and P-selectin, formation of platelet-platelet and platelet-leukocyte aggregates and particle size were examined. RESULTS: No significant difference between the placebo and the digitoxin group (digitoxin levels 17-42 nmol/l) was found, neither on a global level nor for any isolated parameter. CONCLUSIONS: Theory and in vitro data suggest that digitoxin treatment could activate platelets. No evidence for this was found in healthy volunteers. This observation is strengthened by the unequivocal results for all parameters measured. However, thrombosis-prone patients with heart failure and/or atrial fibrillation may respond differently to digitalis therapy.

When should heparin preferably be administered during radiofrequency catheter ablation?

RF catheter ablation is complicated by thromboembolism in about 1% of patients. Limited knowledge exists concerning when and how to use anticoagulation or antithrombotic treatment. We studied the activation of coagulation (prothrombin fragment 1 + 2 [PF1 + 2] and D-dimer), platelets (beta-thromboglobulin [beta-TG]) and fibrinolysis (plasmin-antiplasmin complexes [PAP]) during RF ablation of accessory pathways in 30 patients. They were randomized to receive heparin (100 IU/kg, intravenously) (1) immediately after introduction of the femoral venous sheaths (group I) or (2) after the initial electrophysiological study, prior to the delivery of RF current (groups II and III). Group II additionally received saline irrigation of all femoral sheaths. After the initial bolus, 1,000 IU of heparin was supplied hourly in all groups. Within groups II and III, median plasma values of PF1 + 2 and beta-TG more than tripled (P < or = 0.007) during the diagnostic study and gradually declined during heparin administration despite RF current delivery. Median D-dimer tripled (P = 0.005) and PAP doubled (NS) before heparin administration; then both remained around the upper reference values. In the early heparin group, however, PF1 + 2, D-dimer, and PAP did not rise at all, and beta-TG showed only a slight increase towards the end of the procedure. The differences between group I versus groups II and III were statistically significant prior to the first RF current delivery (PF1 + 2, D-dimer, and beta-TG) and by the end of the procedure (PF1 + 2, D-dimer, and PAP). In conclusion, "late" heparin administration allows hemostatic activation during the initial catheterization and diagnostic study. By administering intravenous heparin immediately after introduction of the venous sheaths, hemostatic activation is significantly decreased. Saline irrigation of the venous sheaths added nothing to late heparin administration.

[Magnetic tomography--new imaging techniques and future perspectives]. / Magnettomografi--nyere bildeteknikker og fremtidsperspektiver.

BACKGROUND: From the very introduction of MRI into medicine, the modality has presented the user a long list of theoretical tissue contrast parameters. The development of MRI has been aimed at turning these theoretical possibilities into practical options. MATERIAL AND METHODS: We give an overview of the new MRI techniques and perspectives for the future based on a literature search and our own experience. RESULTS: Today, the modality offers state-of-the-art anatomical details as well as visualisation of several functional parameters such as perfusion, diffusion, blood oxygen saturation, and tissue temperature. In the near future, MRI may provide absolute quantification of regional perfusion and rate of oxygen consumption in a clinical setting. New vascular and gastrointestinal contrast media will further increase the sensitivity and specificity of MRI. A continuous increase in imaging speed has made MRI capable of providing adequate "fluoroscopic" guidance during interventional procedures, and real-time diagnostic imaging is only few years ahead. INTERPRETATION: The spread of MRI installations will increase as a result of increasing demand for the best and least harmful diagnostic procedure. The main challenge to the MRI community will be to exploit the vast diagnostic possibilities.

[Use of tilt test in the investigation of syncope]. / Bruk av vippetest ved utredning av synkope.

INTRODUCTION: In evaluating syncope, a 45-60 minutes head-up tilt test at 60 degrees with or without pharmacological stimulation is often used. MATERIAL AND METHODS: We report our experience with a faster, ten minute tilt test at 80 degrees with retilting during isoprenaline infusion, on 15 healthy volunteers and 27 patients who subsequently were followed up during a period of 1-3 1/2 years. RESULTS: One volunteer had a positive response (presyncope), while seven of the 27 patients reproduced their clinical symptoms. Among the 20 patients with normal test responses, the clinical course revealed the diagnosis in 11. For the remaining nine patients a definite diagnosis has not been made, but they have not experienced further syncopal episodes. INTERPRETATION: This study demonstrates that the abbreviated tilt test is useful for evaluating recurrent vasovagal and orthostatic syncope.

[Magnetic resonance--historical and theoretical basis]. / Magnetisk resonans--historikk og teoretisk grunnlag.

Magnetic resonance (MR) imaging is a fast developing modality that has become an indispensable diagnostic tool at numerous disease states. The first MR imager in Norway was installed in 1986; by the end of 1999 Norway will have a total of 39 units, approximately one unit per 114,000 inhabitants. MR technique uses radiowaves and magnetic fields, and no ionising radiation is involved. Imaging is based on the fact that all biological tissues are magnetized when placed in a strong, static magnetic field. Short radiofrequency pulses set the tissue magnetic vector into rotation, and the vector induces electric currents in a receiver coil. The electric signals are spatially encoded by means of magnetic field gradients, thus enabling image reconstruction by means of Fourier transformation. The signal intensities can be made dependent on several tissue parameters, thus creating several unique image contrast possibilities.

Late onset postpartum thrombocytosis in preeclampsia.

BACKGROUND: During pregnancy, changes in blood coagulation and fibrinolysis create a hypercoagulable state. In the puerperium this thrombogenicity is even higher, and the chance of developing thromboembolism is 3-5 times higher in this period than during pregnancy. In preeclampsia, platelets are activated and play a substantial role in the pathogenesis of the disease. Systematic information on longitudinal changes in platelet number and size postpartum after normotensive and preeclamptic pregnancies is not available. METHODS: We measured platelet number, mean platelet volume and the median volume of the 20% largest platelets in eleven preeclamptic and eleven normotensive pregnant women matched for mode of delivery. The blood samples were taken antepartum and every 2-3 days in the postpartum period until the platelet count decreased/normalized. RESULTS: In the preeclamptic group, the platelet count increased significantly from 240x10(9)/l antepartum to 621x10(9)/l on day 6-14 postpartum (p<0.01). In the control group, the platelet count increased from 214x10(9)/l antepartum to 251x10(9)/l on day 2-5 (p<0.01) and 351x10(9)/l on day 6-14 postpartum (p<0.01). The platelet count was significantly higher in the preeclamptic than in the control group 6-14 days postpartum (p<0.01). Antepartum, mean platelet volume and the median of the 20% largest platelets were significantly higher in the preeclamptic than in the control group. CONCLUSION: The platelet count is significantly increased postpartum both after normotensive, and 2-3 fold more after preeclamptic pregnancies. The time to peak values is between 6-14 days, usually at a time when patients are discharged from hospital.

[Computer-based interpretation of ECG--guiding or misleading?]. / Datamaskintolking av EKG--veiledende eller villedende?

Computerised ECG diagnostic programs occasionally provide erratic diagnoses, and false diagnostic suggestions may mislead the physician. We wanted to investigate whether a diagnostic computer program guides or misleads the ECG interpretation in the emergency room. A panel of 20 first-line physicians from the Medical Department at Ullevål Hospital, Oslo, Norway each described sets of ten ECGs, composed from a selection of ten excellent and ten wrong computer interpretations, randomly with or without the print-out of this diagnosis. The presence of correct computer diagnosis resulted in 58% correct conclusions by the physicians, against 30% in the absence of the computers conclusions (p < 0.005). Whether an incorrect computer diagnosis was provided or not, did not significantly influence the physicians' conclusions. Among the physicians, the best performing third benefitted most from the presence of a good computer interpretation, whereas the poor performers did not even recognise the help provided. Computer-based ECG diagnoses seem to be helpful to emergency ward physicians, but a certain level of ECG experience is required to utilise the program.

MR urography: the future gold standard in paediatric urogenital imaging?

BACKGROUND: Examination of the paediatric urogenital tract is traditionally performed using methods that utilise ionising radiation, such as intravenous urography (IVU), computerised tomography (CT), voiding cystourethrography (VCU), and scintigraphy, in addition to ultrasound (US). OBJECTIVE: To determine the potential and effectiveness of MR urography (MRU) in infants and children. Materials and methods. 44 MRU examinations were prospectively performed in 39 patients (21 infants, mean age 3.5 months, and 18 children, mean age 6 years 2 months) with known or suspected pathology of the urinary tract. Non-enhanced, fast spin-echo sequences (TSE) were performed in all patients. In 70 % of the patients a contrast-enhanced, fast gradient-echo sequence (TFE) was included. The dynamic sequence was prolonged and supplemented with furosemide provocation in some patients with suspected urinary-tract obstruction. RESULTS: Nine percent of examinations were non-diagnostic or interrupted due to movement. MRU contributed additional information in 66 %. Nine patients with suspected urinary-tract obstruction were examined with both contrast-enhanced MRU and scintigraphy. Three MRU examinations were less informative and one equal to scintigraphy when obstruction was the diagnosis. When using a technique with a prolonged dynamic sequence, including frusemide provocation, four MRU examinations were equal and one was superior to scintigraphy. CONCLUSIONS: MRU has the potential to replace traditional diagnostic methods which use ionising radiation in paediatric patients. Further studies are needed before definite conclusions can be drawn.