Prevalence and complications of MRI scans of cochlear implant patients : English version.

BACKGROUND: Cochlear implants (CI) are the preferred method of treatment for patients with severe to profound bilateral sensorineural hearing loss and unilateral deafness. For many years, because of the magnetic field applied during magnetic resonance imaging (MRI) examinations, MRI examinations were contraindicated for CI patients or feasible only under specific circumstances. MRI examinations of CI recipients entail complications and therefore preventive measures have to be considered. The aim of this study was to evaluate the prevalence of MRI scans in CI recipients and the occurrence of complications and furthermore to investigate the preventive measures taken in radiological daily routine. MATERIALS AND METHODS: A retrospective questionnaire was sent to 482 patients that received CIs from 1999-2013. Details of the MRI examination and subjective and objective incidents during and after the MRI scan were evaluated. RESULTS: A total of 204 CI recipients answered the retrospective questionnaire (42.3 %). Twenty patients (9.8 %) with 23 implants underwent a total of 33 MRI scans with their cochlear implant in place. In 16 cases the scanned region was the head (49 %). Preventive measures in the form of head bandages were taken in 20 cases (61 %). The most common complication was pain in 23 cases (70 %) and the most serious complication was the dislocation of the internal magnet in 3 cases (9 %). CONCLUSIONS: The number of CI recipients undergoing MRI scans is high. Possible complications and preventive measures attract too little attention in radiological daily routine.

[Prevalence and complications of MRI scans of cochlear implant patients: German version]. / Häufigkeit und Komplikationen von MRT-Untersuchungen bei Cochlea-Implantat-Patienten: German version.

BACKGROUND: Cochlear implants (CI) are the preferred method of treatment for patients with severe to profound bilateral sensorineural hearing loss and unilateral deafness. For many years, because of the magnetic field during magnetic resonance imaging (MRI) examinations, MRI examinations were contraindicated for CI patients or feasible only under specific circumstances. MRI examinations of CI recipients entail complications and therefore preventive measures have to be considered. The aim of this study was to evaluate the incidence of MRI scans in CI recipients and the occurrence of complications, and furthermore to investigate the preventive measures taken in radiological daily routine. MATERIALS AND METHODS: A retrospective questionnaire was sent to 482 patients that received CIs from 1999-2013. Details of the MRI examination and subjective and objective incidents during and after the MRI scan were evaluated. RESULTS: A total of 204 CI recipients answered the retrospective questionnaire (42.3%). Twenty patients (9.8%) with 23 implants underwent a total of 33 MRI scans with their cochlear implant in place. In 16 cases the scanned region was the head (49%). Preventive measures in the form of head bandages were taken in 20 cases (61%). The most common complication was pain in 23 cases (70%) and the most serious complication was the dislocation of the internal magnet in 3 cases (9%). CONCLUSIONS: The number of CI recipients undergoing MRI scans is quite high. Possible complications and preventive measures attract too little attention in radiological daily routine.

MRI-Based Estimation of Scalar Cochlear-Implant Electrode Position.

The position of the cochlear-implant electrode is important to audiological outcomes after cochlear implantation. The common technique to evaluate the intracochlear electrode's position involves the use of ionized radiation in MSCT, DVT, or flat-panel tomography (FPT). Recent advances in knowledge regarding the handling of MRI artifacts in cochlear implantees indicate that estimating the intracochlear electrode's position with an MRI could be possible. This study's aim was to evaluate the ipsilaterally position of electrodes using MRI at 1.5 T. In a retrospective study of 10 implantees with postoperative need for MRI scanning, we evaluated the intrascalar electrode's position using a T2-weighted sequence at 1.5 T. We compared the resulting estimate of the intracochlear position with the estimates from the postoperative FPT scan and the intraoperative NRT ratio. For each ear, the MRI-estimated scalar position corresponded with the estimated positions from the FPT and NRT ratio. For eight ears, a scala tympani's position was observed in the MRI. In one case, an electrode scalar translocation was found. In one case, the scala vestibuli's position was observed. Thus, MRI-based estimation of the scalar position of a cochlear-implant electrode is possible. Limitations to this method include implant-specific magnet and fixation configurations, which can cause complications.

[Computerized tomographic study of medieval coffins]. / Computertomographische Untersuchung mittelalterlicher Särge.

Two medieval coffins containing neonates were examined by CT. The advantages of using computed tomography, compared with conventional x-ray techniques, for analysing various objects within a receptacle are demonstrated.

Age-at-death diagnosis and determination of life-history parameters by incremental lines in human dental cementum as an identification aid.

Incremental lines in acellular extrinsic fiber cementum of 91 roots from 80 freshly extracted teeth have been investigated for a verification of the suitability of pathological teeth for a valid age-at-death diagnosis. Independent from tooth type, the accuracy of histological age-at-death diagnosis is clearly a function of a tooth's pathological state. Various periodontal diseases lead to a reduced number of incremental lines, while teeth with a sufficient nutritional support of their root showed a deviation of the histological age from the known actual age of 2-3 years only. For all patients, a detailed query concerning a variety of life-history parameters was established. We are able to show that especially previous pregnancies, skeletal traumata and renal diseases which all have a marked influence on the calcium metabolism result in hypomineralized incremental lines. The year of production of these hypomineralized lines could be dated precisely. Differential quality of incremental lines can, therefore, serve as a valuable tool in identification cases.

Feeding ecology of the stone and pine marten revealed by element analysis of their skeletons.

Feeding habits of free-ranging martens (Martes martes and Martes foina) are evaluated by means of trace element and stable carbon isotope analyses of their skeletons. This investigation was carried out as an inter-disciplinary project of both wildlife biology and physical anthropology. As a result, data are obtained on the feeding ecology of the two species; in addition, a baseline is provided for dietary reconstruction of past human populations. Both species of martens are omnivorous feeders, M. martes being slightly more carnivorous than M. foina. Diversity of dietary intake with respect to plant food and animal protein is only one-third of the maximum divergence between strict herbivores and carnivores.

Identification of medieval human soft tissue remains in an advanced state of decomposition.

Naturally preserved human soft tissue remains from mediaeval burials (11-13th century A. D.) were investigated histologically after azocarmine/aniline alcohol (AZAN) or keratinprekeratin-mucin (KPM) staining. The tissue remnants were in an advanced state of decomposition; they were completely collapsed and had lost their macroscopic characteristics. After rehydration, thin sectioning, and staining, microscopic properties permitted tissue identification, although differential staining of tissue components did not necessarily correspond with the expected results based on fresh tissue. The techniques and results presented in this paper are relevant for both anthropological and forensic purposes.

Reconsideration of bone postmortem interval estimation by UV-induced autofluorescence.

Assessing the UV-fluorescence of a freshly cut cross section of the compact parts of a bone is often recommended as a first step to estimate the postmortem interval (PMI) of skeletal remains. Opinions differ concerning the cause of fluorescence and on how to categorize fluorescent properties as well as the significance of fluorescent characteristics in correlation with the PMI. In this study we evaluated the UV-fluorescence of over 200 bones with known PMI to reassess the diagnostic value of this method for differentiating between historical and recent skeletal remains. It could be shown that there is a correlation between the PMI and fluorescence colour, but not with fluorescence intensity. Furthermore, the quality of two UV-fluorescence test possibilities based on fluorescence colour was assessed by calculating the individual test efficiency, sensitivity and specificity. The results showed that blue bone fluorescence, as well as blue fluorescence combined with other colours (mainly yellow) does not allow the observer to draw any conclusions about sample age. Only overall yellow fluorescence may indicate a historical specimen. But still, 2% of all forensically relevant samples were falsely excluded, making bone fluorescent properties inappropriate as the sole criterion for deciding whether a specimen is included or excluded for further forensic investigation.

Metastasizing carcinoma in a medieval skeleton: differential diagnosis and etiology.

The paper describes the skeleton of an aged adult male from the Middle Ages who most probably suffered from a bronchogenetic carcinoma. The differential diagnosis is based on macroscopic and microscopic examination, X-ray studies, and trace element analysis. Hypothesis for the etiology of the disease are discussed.

[Environmental history as an anthropologic topic. Contribution to "chemical anthropology"]. / Umweltgeschichte als anthropologische Fragestellung. Beitrag einer "Chemical Anthropology".

Human population history is firmly connected with temporal and regional changes of the environment. Whether natural or anthropogene, alteration of environmental features lead to changes of human life-style and to the development of adaptive strategies. The demand of resources for his subsistence has led man to diverse impacts on his environment since ever. Thus, environmental history is a scientific topic for anthropologists. The research potential of trace element studies of excavated human skeletons for the reconstruction of natural and socio-cultural environments as well as for distribution patterns of hazardous substances is outlined for the European Middle Ages. The scientific value of unravelling past man/environment-interrelationships for both the historical and applied sciences and the place of any "chemical anthropology" within this context is discussed.

[Trace elements in buried human bones and their value. A review]. / Spurenelemente in bodengelagerten menschlichen Knochen und ihre Aussagen. Ein Uberblick.

Since more than a decade, the trace element content of archaeological human bones is analyzed by physical anthropologists. Some of these elements give clues to the diets of ancient populations, others serve in estimating weaning age and the length of the active reproductive time span in human females. Therefore, trace element analysis becomes very important for palaeodemography and palaeoecology. On the other hand, a lot of basic research still has to be carried out, especially concerning the alteration of trace element concentrations in ancient bones either by soil processes or by microorganisms. The lack of reference series is obvious. Recommendations for the techniques to be applied are given, the parameters which may bias the interpretation of the data are discussed and the diagnostic potential of trace element analysis is demonstrated.

[Etiology of the cribra orbitalia: effect of amino acid profile in bone collagen and the iron content of bone minerals]. / Zur Atiologie der Cribra orbitalia: Auswirkungen auf das Aminosäureprofil im Knochenkollagen und den Eisengehalt des Knochenminerales.

As long as cribra orbitalia manifests itself as an isolated skeletal lesion in excavated human skeletons, it is mostly diagnosed as being of nutritional origin, especially iron deficiency anemia. Since both iron and vitamin C function as cofactors at the hydroxylation of the amino acids proline and lysine in collagen, both amino acid analyses of bone collagen and the determination of bone mineral iron content was carried out at ten medieval skeletons with cribra orbitalia, opposed to ten morphologically healthy individuals from the same skeletal series. The skeletons with cribra orbitalia were significantly depleted with respect to OHpro (the OHpro/Pro-ratio being 16.9% lower than in the control group), but did not differ from the healthy individuals with respect to OHlys and iron content. No correlation was found between proline hydroxylation and age at death or degree of the disease. The data do not support the iron deficiency hypothesis. Most probably, vitamin C deficiency was responsible for the difference between diseased and morphologically healthy individuals. A combination of protein and elemental analysis of excavated bones should thus be suitable for the detection of deficient hydroxylation and its etiology: iron or vitamin C deficiency.

[Identification of the skeleton of Georg Christoph Lichtenberg]. / Die Identifikation des Skelettes von Georg Christoph Lichtenberg.

To reveal the morbidity of George Christoph Lichtenberg, his skeleton was exhumed in May 1983. This paper deals with the identification of the skeleton as well as with its pathology. Since Lichtenberg left detailed knowledge about his bodily appearance in his own writings, and so did his contemporaries, the identity of the skeleton can be taken for sure because of the good correspondence of several morphological and pathological features.

Life style, subsistence and mortality in the Slavonic village at Espenfeld (Kr. Arnstadt, FRG). A trace element study.

Since the burial site of the Slavonic settlement at Espenfeld, Germany (10th to 12th century AD), has been completely excavated, the skeletons are representative of the historic population. This skeletal series has also been intensively investigated both archaeologically and anthropologically. It thus belongs to the kind of museum specimens which should not be left apart from any further study made possible by technological improvements. Analysis of elements Ca, P, Sr, Ba, Zn, Pb and As from compact bone specimens of a subsample of this series was carried out to get a more detailed knowledge on the population's life style. After a consideration of site-specific diagenesis, reconstruction of subsistence was possible for both adults and children. The assessment of weaning practice revealed insights into childcare. Special consideration was given to hazardous elements and their influence on infant morbidity. Also, a presumed genetic relationship between certain individuals based on morphological traits was paralleled by a striking similarity of trace element profiles, suggesting that bone chemistry might also permit the differentiation of microenvironments.

Trace elements in excavated human hair.

Concentrations of the elements Ca, Sr, Mg, Zn and Cu were determined in excavated hair specimens and adherent, most probably soil remains from two sites in Germany. Though soil contamination obviously has occurred, the two groups could be distinguished by differential trace element contents in the hair samples. The trace element concentrations might be interpreted in terms of nutritional intake, the results being corroborated by preceding bone analyses and the different local and social settings. Hair decomposition is discussed.

Biochemical and palaeopathological investigations on weaning and infant mortality in the early Middle Ages.

Weaning age of the children of the early medieval population at Wenigumstadt (Ldkr. Aschaffenburg, southern Germany, 500-700 AD) was estimated by stable nitrogen isotope analysis of bone collagen. The onset of weaning was by one year of age, when solid vegetal food subsequently replaced breast milk. In total, the change from mother's milk to solid adult food took about three years, the infants being fully weaned at this age. While the growing infant was sufficiently supported in utero and during the first months of life, the weanling's diet was insufficient for further growth and development. Starting with about 18 months of age, more and more symptoms of malnutrition are detectable on the skeletal remains, and the peak of both morbidity and mortality is reached at four years of age. Especially unspecific stress markers like Harris' lines and enamel hypoplasia clearly indicate the infants' risk of falling ill or die between three and four years of age. Malnutrition weakens the immune response, therefore the majority of inflammations detectable on the skeleton are found among the inadequately nourished children. The assumption that weaning is responsible for pathological skeletal lesions and early death in history is thus supported by archaeometry.

On the validity of individual age-at-death diagnosis by incremental line counts in human dental cementum. Technical considerations.

Histological analysis of 91 roots from 80 freshly extracted teeth from patients with known calendar age and life-history parameters revealed that the validity of a chronological age-at-death diagnosis based on the count of incremental lines in human dental cementum is essentially dependent from two parameters: method of analysis, and pathological state of the investigated tooth. In this paper, we want to contribute to the establishment of a methodological standard procedure by comparison of our own results with otherwise published research designs. We conclude that as long as the necessary prerequisites are met, the quantitative analysis of cementum annulli will lead to a rather precise chronological age-at-death diagnosis. In addition, a qualitative analysis permits the ontogenetic dating of certain individual life-history parameters (e.g. previous pregnancies).

[Serum proteins in human skeletal remains]. / Serumproteine in menschlichem Skelettmaterial.

The analysis of non-mineralbound, non-collagenous proteins from ancient Peruvian human bones with electrophoretical methods, SDS-polyacrylamide-electrophoresis and isoelectric focusing, results in molecular weight bands on the one hand and a pH-gradient distribution on the other hand, which are perhaps connected with polymorphic serum proteins. A specific protein identification is possible with immunological methods.

[Correlations between cribra orbitalia, archeometric findings on the skeleton and habitat conditions]. / Zusammenhänge zwischen Cribra orbitalia, archäometrischen Befunden am Skelett und Habitatbedingungen.

The interpretation of cribra orbitalia as an isolated skeletal lesion is mainly based on malnutrition, in particular in terms of iron deficiency or vitamin C deficiency. A chronic iron deficiency anemia should result in both a reduced iron content of the skeleton and an underhydroxylation of the amino acid proline with the consequence of a less stable collagen matrix of the bone. The latter holds also for a vitamin C deficiency. Trace element and amino acid analyses were independently applied to subsamples of two early medieval human skeletal series to test whether a relation between cribra orbitalia and skeletal iron content and amino acid hydroxylation was detectable. For one of these series (Nusplingen, district Balingen, Schwäbische A1b), habitat specific properties have already been assumed to be responsible for an insufficient iron supply of the inhabitants. Both archaeometric approaches led to a verification of the malnutrition hypothesis, but for advanced states of the skeletal lesion only. Less affected individuals did not reveal any of the expected relationships. Possible adaptive subsistence strategies are discussed which might compensate for such unfavourable living conditions.

Causes of infant mortality in the Middle Ages revealed by chemical and palaeopathological analyses of skeletal remains.

In most prehistoric and historic populations, mortality of small infants is very high. Causes of death are mainly discussed in analogy to the situation in modern preindustrial societies. The children are at high risk to fall ill or even die especially in times of weaning. Trace element analysis of the skeletal remains of small infants excavated in Schleswig (northern Germany, 11th/12th century AD) led to the estimation of weaning age as well as to the reconstruction of a stepwise substitution of mothers' milk by other food items. Subsequent palaeopathological analysis confirmed high mortality in this age-group. Thus, causes of death of small infants in a medieval town can be outlined.