Iron overload: accuracy of in-phase and out-of-phase MRI as a quick method to evaluate liver iron load in haematological malignancies and chronic liver disease.

OBJECTIVES: The purpose of this prospective study was to evaluate the accuracy of in-phase and out-of-phase imaging to assess hepatic iron concentration in patients with haematological malignancies and chronic liver disease. METHODS: MRI-based hepatic iron concentration (M-HIC, µmol g(-1)) was used as a reference standard. 42 patients suspected of having iron overload and 12 control subjects underwent 1.5 T in- and out-of-phase and M-HIC liver imaging. Two methods, semi-quantitative visual grading made by two independent readers and quantitative relative signal intensity (rSI) grading from the signal intensity differences of in-phase and out-of-phase images, were used. Statistical analyses were performed using the Spearman and Kruskal-Wallis tests, receiver operator curves and κ coefficients. RESULTS: The correlations between M-HIC and visual gradings of Reader 1 (r = 0.9534, p < 0.0001) and Reader 2 (r = 0.9456, p < 0.0001) were higher than the correlations of the rSI method (r = 0.7719, p < 0.0001). There was excellent agreement between the readers (weighted κ = 0.9619). Both visual grading and rSI were similar in detecting liver iron overload: rSI had 84.85% sensitivity and 100% specificity; visual grading had 85% sensitivity and 100% specificity. The differences between the grades of visual grading were significant (p < 0.0001) and the method was able to distinguish different degrees of iron overload at the threshold of 151 µmol g(-1) with 100% positive predictive value and negative predictive value. CONCLUSION: Detection and grading of liver iron can be performed reliably with in-phase and out-of-phase imaging. Liver fat is a potential pitfall, which limits the use of rSI.

Magnetic resonance imaging in pediatric elbow fractures.

PURPOSE: Magnetic resonance imaging (MRI) evaluation of pediatric elbow trauma with or without a visible fracture on radiography. MATERIAL AND METHODS: MRI was performed in the acute phase in 25 children with an elbow injury. Nine patients with an elbow effusion only on radiographs and 16 with a fracture or luxation seen on radiographs underwent subsequent MRI. No sedation was used. RESULTS: MRI revealed eight occult fractures (89%) in seven out of nine patients who had only an effusion on radiographs. Based on MRI findings, septic arthritis was suspected in one patient. Two patients out of five with a supracondylar fracture on the radiograph had a cartilage lesion in the humerus. MRI depicted a 3-mm gap on the articular surface in two patients with a lateral condyle fracture, a more accurate fracture location in two patients than the radiographs, and an additional occult fracture in two patients. MRI showed a fracture not seen on radiographs in two of three patients with prior luxation. CONCLUSION: MRI is a sensitive and accurate method in the diagnosis of pediatric elbow injuries, especially when only an effusion is present on radiographs. Occult fractures are more common in pediatric patients with elbow injury than reported earlier.

Influence of film digitization on radiological interpretation.

Our objective was to evaluate the influence of changing from analogue to digital imaging on interobserver and intraobserver image interpretation. Three radiologists interpreted 96 three image series of occipitomental radiographs of paranasal sinuses from the films and from the corresponding digitized images from the screen. Images were classified according to degree of abnormality as either normal, with mucosal thickening of less than 5 mm, with mucosal thickening of 5 mm or more, total opacity, air-fluid level or polyp or cyst of maxillary sinuses. In the present study we found that there were more differences between two radiologist's interpretations with a single method than in a single radiologist's interpretations between the methods, although radiologists interpreted fewer pathological findings from the digitized images than from the corresponding films. Our data show that the results of image interpretation are preferentially dependent on the reader rather than on the method of reading.

Acute phase response in reindeer after challenge with Escherichia coli endotoxin.

The serum concentrations of two acute phase proteins (APPs), haptoglobin (Hp) and serum amyloid-A (SAA), were monitored in reindeer after challenge with endotoxin. Four adult female reindeer received either 0.1 microg/kg Escherichia coli 0111:B4 lipopolysaccharide B or saline solution intravenously. At the second challenge, the treatments were reversed. In addition to the APPs, changes in blood chemistry and rectal temperature were monitored. The endotoxin challenge caused a significant increase in SAA (peak 48 h) and a sharp decrease (8-12 h) of serum iron concentrations in all animals. The mean Hp concentration increased at 8 h and remained elevated until 48 h, but no statistically significant differences were found. This investigation demonstrates that challenge with a single-bolus dose of E. coli endotoxin can activate the acute phase response (APR) and SAA appears to be a more sensitive indicator of the APR than Hp during bacterial infection in reindeer.

Meat quality and transport stress of cattle.

This study evaluated the effect of transport time up to 14 hours and the effects of vehicle design on animal welfare, stress and meat quality. 18 transports (six short, medium and long) with a total of 486 animals (118 sample animals, heifers and bulls) were carried out on commercial vehicles in summer 2000 and winter 2001. Animal welfare and stress were evaluated by blood serum parameters, heart rate monitoring, behaviour recording and occurrence of carcass bruising. Meat quality was evaluated by post mortem muscle glycogen content, pH value, temperature, drip loss, colour and tenderness measurements. Heifers had lower heart rates than young bulls during loading (95 vs 114 beats per minute, bpm), whereas during transport, both had an average heart rate of 100 bpm, furthermore during unloading, heifers had higher heart rates than bulls (109 vs 100 bpm). Blood sampling during unloading could have marginally increased heart rates during the unloading procedure. Studied cattle had lower heart rates during medium and long distance transports compared with short transports. Monitoring of animal behaviour during transport showed that the former settled down faster than the latter. Single- and two-animal pens in medium and long distance vehicles prevented nervous and stressful movements of cattle, which were more prominent in large pens of short distance lorry. Present results suggest that larger pens of three or four animals could increase cattle stress during transport. Moreover during unloading, cattle loaded in single- or two-animals pens had significantly lower blood cortisol content than those loaded in larger groups of three or four animals (P < 0.01). The amount of severe carcass bruising was highest in animals transported over short times and loaded into groups of four cattle. Severe damages occurred most often on perianal and hipbone area of the carcass surface. Present results showed that muscle glycogen level was highest after long transport. These animals were fed more regularly from the last feeding up to stunning than medium or short distance animals. Animals in single-pens had the highest muscle glycogen level. Transport distance or number of animals in one pen had a minor effect on muscle pH values or temperatures during 24 hours post mortem (pm). Drip loss of the M. longissimus dorsi (LD) was highest after long transport, but animal number in one pen had no effect on drip loss. Colour of the LD muscle was independent on transport conditions. Light colour of three animal groups resulted from high amounts of heifers, which had lighter colour than bulls. All meat samples were quite tender. However, heifers had significantly tender meat than young bulls (P < 0.001). Higher amounts of heifers had the most tender meat after short transports. Mean DFD (dark, firm, dry) meat occurrence was 2.1% in this project, DFD frequency was lowest after short, then after long and highest after medium distance transports. Because of not evenly distributed numbers of bulls (low) and heifers (high) it was difficult to compare short and long distance transport effects.

Individually coded telemetry: a tool for studying heart rate and behaviour in reindeer calves.

The aim of the study was to test the performance of a silver wire modified version of the coded telemetric heart rate monitor Polar Vantage NV (PVNV) and to measure heart rate (HR) in a group of captive reindeer calves during different behaviour. The technical performance of PVNV HR monitors was tested in cold conditions (-30 degrees C) using a pulse generator and the correlation between generated pulse and PVNV values was high (r=0.9957). The accuracy was tested by comparing the HR obtained with the PVNV monitor with the standard ECG, and the correlation was significant (r=0.9965). Both circadian HR and HR related to behavioural pattern were recorded. A circadian rhythm was observed in the HR in reindeer with a minimum during night and early morning hours and maximum at noon and during the afternoon, the average HR of the reindeer calves studied being 42.5 beats/min in February. The behaviour was recorded by focal individual observations and the data was synchronized with the output of the HR monitors. Running differed from all other behavioural categories in HR. Inter-individual differences were seen expressing individual responses to external and internal stimuli. The silver wire modified Polar Vantage NV provides a suitable and reliable tool for measuring heart rate in reindeer, also in natural conditions.