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Daniela Prayer

Publications and source records attributed to Daniela Prayer.

At least 19 recordsLinked to original sources
PubMed2007

Central nervous system-related permanent consequences in patients with Langerhans cell histiocytosis.

BACKGROUND: Permanent consequences in Langerhans cell histiocytosis (LCH) are irreversible late sequelae related to the disease that may severely impair the quality of life of survivors. The frequency and pattern of permanent consequences affecting the central nervous system (CNS) remains to be determined. PROCEDURE: In this single center study, 25 LCH patients observed for a median time of 10 years 3 months underwent a uniform thorough follow-up program including neuropsychological testing and electrophysiological evaluation. RESULTS: Overall permanent consequences were seen in 9 of 25 patients. Intracranial abnormalities were the most frequent including diabetes insipidus (DI) in seven patients, anterior pituitary deficiencies in five patients, and neurodegenerative CNS disease in five patients. No patient had overt neurological symptoms upon neurological evaluation, but psychological testing revealed subtle deficits in short-term auditory memory (STAM) in 14 patients. Brain stem evoked potentials showed abnormalities in four of nine tested patients, all of these four had neurodegeneration on MRI. CONCLUSION: Psychoneuroendocrine sequelae were found in an unexpectedly high number of patients in this single center study. Long-term follow-up focusing on such sequelae are important in LCH survivors, in order to detect early deficits, to monitor the evolution of the disease, and to provide specific support.

Adolescent↗
PubMed2006

MRI investigation of normal fetal lung maturation using signal intensities on different imaging sequences.

To purpose of this paper is to study the relation between normal lung maturation signal and changes in intensity ratios (SIR) and to determine which magnetic resonance imaging sequence provides the strongest correlation of normal lung SIs with gestational age. 126 normal singleton pregnancies (20-37 weeks) were examined with a 1.5 Tesla unit. Mean SIs for lungs, liver, and gastric fluid were assessed on six different sequences, and SIRs of lung/liver (LLSIR) and lung/gastric fluid (LGSIR) were correlated with gestational age for each sequence. To evaluate the feasibility of SIRs in the prediction of the state of the lung maturity, accuracy of the predicted SIRs (D*) was measured by calculating relative residuals (D*-D)/D for each sequence. LLSIRs showed significant changes in every sequence (p<0.05), while LGSIRs only on two sequences. Significant differences were shown for the mean of absolute residuals for both LLSIRs (p<0.001) and for LGSIRs (p=0.003). Relative residuals of LLSIRs were significantly smaller on T1-weighted sequence, whereas they were significantly higher for LGSIRs on FLAIR sequence. Fetal liver seems to be adequate reference for the investigation of lung maturation. T1-weighted sequence was the most accurate for the measurement of the lung SIs; thus, we propose to determine LLSIR on T1-weighted sequence when evaluating lung development.

Feasibility Studies↗
PubMed2006

Diversity of cytogenetic and pathohistologic profiles in glioblastoma.

We present a small series of patients with primary glioblastoma multiforme (GBM), and combine individual genetic data with pathohistologic characteristics and clinical outcome. Eighteen patients (12 men, 6 women, median age 51 years) with histologically proven GBM underwent surgical debulking followed by radiotherapy. Fifteen received concomitant chemotherapy. Histologic typing, immunohistochemistry for CD34, karyotypic analysis, and classification of the pattern of neovascularization was done in all patients. In 12/18, we performed methylation-specific polymerase chain reaction of the MGMT gene (O-6-methylguanine-DNA methyltransferase). The survival duration of patients spanned 3-58 months. By classical banding methods, 15/18 patients showed at least one aberration characteristic for primary glioblastoma (+7 in 7/18, deletions of 9p in 10/18 and -10 or deletions from 10q in 8/18 patients). We could not assess whether patients who survived for longer periods showed less complex or fewer aberrations than the patients who survived less than one year. Losses of 6p21(VEGF), 4q27(bFGF), and 12p11 approximately p13 (ING4) were associated with the "bizarre" pattern of neoangiogenesis. Methylation of the MGMT promoter was found in 3/12 patients. Even in this small series, the main characteristic of GBM was its diversity regarding all investigated histologic and genetic characteristics. This extreme diversity should be considered in the design of targeted therapies in GBM.

Adolescent↗
PubMed2006

A new look at the fetus: thick-slab T2-weighted sequences in fetal MRI.

Although magnetic resonance imaging (MRI) of the fetus is considered an established adjunct to fetal ultrasound, stacks of images alone cannot provide an overall impression of the fetus. The present study evaluates the use of thick-slab T2-weighted MR images to obtain a three-dimensional impression of the fetus using MRI. A thick-slab T2-weighted sequence was added to the routine protocol in 100 fetal MRIs obtained for various indications (19th to 37th gestational weeks) on a 1.5 T magnet using a five-element phased-array surface coil. Slice thickness adapted to fetal size and uterine geometry varied between 25 and 50mm, as did the field of view (250-350 mm). Acquisition of one image took less than 1s. The pictorial essay shows that these images visualize fetal anatomy in a more comprehensive way than is possible with a series of 3-4mm thick slices. These thick-slab images facilitate the assessment of the whole fetus, fetal proportions, surface structures, and extremities. Fetal pathology may be captured in one image. Thick-slab T2-weighted images provide additional information that cannot be gathered from a series of images and are considered a valuable adjunct to conventional 2D MR images.

Female↗
PubMed2006

MRI of fetal acquired brain lesions.

Acquired fetal brain damage is suspected in cases of destruction of previously normally formed tissue, the primary cause of which is hypoxia. Fetal brain damage may occur as a consequence of acute or chronic maternal diseases, with acute diseases causing impairment of oxygen delivery to the fetal brain, and chronic diseases interfering with normal, placental development. Infections, metabolic diseases, feto-fetal transfusion syndrome, toxic agents, mechanical traumatic events, iatrogenic accidents, and space-occupying lesions may also qualify as pathologic conditions that initiate intrauterine brain damage. MR manifestations of acute fetal brain injury (such as hemorrhage or acute ischemic lesions) can easily be recognized, as they are hardly different from postnatal lesions. The availability of diffusion-weighted sequences enhances the sensitivity in recognizing acute ischemic lesions. Recent hemorrhages are usually readily depicted on T2 (*) sequences, where they display hypointense signals. Chronic fetal brain injury may be characterized by nonspecific changes that must be attributable to the presence of an acquired cerebral pathology. The workup in suspected acquired fetal brain injury also includes the assessment of extra-CNS organs that may be affected by an underlying pathology. Finally, the placenta, as the organ that mediates oxygen delivery from the maternal circulation to the fetus, must be examined on MR images.

Brain Injuries↗
PubMed2006

Fetal MRI of the urinary system.

The assessment of the urinary system is typically performed by ultrasound. Nevertheless, an ultrasound may be inconclusive in fetuses with renal diseases that result in anhydramnios or oligohydramnios. In such cases, and in other cases in which ultrasound is limited, further investigation with MR should be considered. In the following article, we will provide an overview of the most commonly encountered disorders of the urinary system and their appearance on fetal MR imaging. Fetal MR imaging can accurately diagnose a wide variety of urinary tract disorders and must be seen as a valuable complementary tool to ultrasound in the assessment of the urinary system, particularly in cases of inconclusive ultrasound findings.

Female↗
PubMed2006

Fetal abdominal magnetic resonance imaging.

This review deals with the in vivo magnetic resonance imaging (MRI) appearance of the human fetal abdomen. Imaging findings are correlated with current knowledge of human fetal anatomy and physiology, which are crucial to understand and interpret fetal abdominal MRI scans. As fetal MRI covers a period of more than 20 weeks, which is characterized not only by organ growth, but also by changes and maturation of organ function, a different MR appearance of the fetal abdomen results. This not only applies to the fetal intestines, but also to the fetal liver, spleen, and adrenal glands. Choosing the appropriate sequences, various aspects of age-related and organ-specific function can be visualized with fetal MRI, as these are mirrored by changes in signal intensities. Knowledge of normal development is essential to delineate normal from pathological findings in the respective developmental stages.

Abdomen↗
PubMed2006

Fetal MR.

Explore the source record for details and available documents.

Female↗
PubMed2006

Normal renal development investigated with fetal MRI.

OBJECTIVE: To evaluate age-dependent changes in fetal kidney measurements with MRI. PATIENTS AND METHODS: Fetal MRI examinations were used to study the kidney length (218 fetuses), signal intensities of renal tissue, renal pelvis, and liver tissue on T2-weighted images (223 fetuses), and the whole-kidney apparent diffusion coefficient (107 fetuses). A 1.5 T superconducting unit with a phased array coil was used in patients from 16 to 39 weeks' gestation. The imaging protocol included T2-weighted single-shot fast spin-echo, T2-weighted balanced angiography and diffusion-weighted sequences. Slice thickness ranged from 3 to 5mm. RESULTS: Fetal kidney length as a function of gestational age was expressed by the linear regression: kidney length (mm)=0.190 x gestational age (d) -8.034 (R(2) = 0.883, p < 0.001). Paired t-test analysis showed a highly statistically significant difference between the ratio of renal tissue signal intensity to renal pelvis signal intensity and the ratio of liver signal intensity to renal pelvis signal intensity on T2-weighted images (t = -50.963, d.f. = 162, p < 0.001), with renal tissue hyperintense to liver tissue. The apparent diffusion coefficient in relation to gestational age was described by the equation: ADC (microm(2)/s) = 0.0302 x square (gestational age (d)) -14.202 x gestational age (d) +2,728.6 (R(2) = 0.225, p < 0.001). CONCLUSION: The length, signal intensity on T2-weighted images, and apparent diffusion coefficient of the fetal kidney change significantly with gestational age. The presented data may help in the prenatal diagnosis of renal anomalies.

Female↗
PubMed2006

MRI of normal fetal brain development.

Normal fetal brain maturation can be studied by in vivo magnetic resonance imaging (MRI) from the 18th gestational week (GW) to term, and relies primarily on T2-weighted and diffusion-weighted (DW) sequences. These maturational changes must be interpreted with a knowledge of the histological background and the temporal course of the respective developmental steps. In addition, MR presentation of developing and transient structures must be considered. Signal changes associated with maturational processes can mainly be ascribed to the following changes in tissue composition and organization, which occur at the histological level: (1) a decrease in water content and increasing cell-density can be recognized as a shortening of T1- and T2-relaxation times, leading to increased T1-weighted and decreased T2-weighted intensity, respectively; (2) the arrangement of microanatomical structures to create a symmetrical or asymmetrical environment, leading to structural differences that may be demonstrated by DW-anisotropy; (3) changes in non-structural qualities, such as the onset of a membrane potential in premyelinating axons. The latter process also influences the appearance of a structure on DW sequences. Thus, we will review the in vivo MR appearance of different maturational states of the fetal brain and relate these maturational states to anatomical, histological, and in vitro MRI data. Then, the development of the cerebral cortex, white matter, temporal lobe, and cerebellum will be reviewed, and the MR appearance of transient structures of the fetal brain will be shown. Emphasis will be placed on the appearance of the different structures with the various sequences. In addition, the possible utility of dynamic fetal sequences in assessing spontaneous fetal movements is discussed.

Brain↗
PubMed2006

Magnetic resonance imaging of the normal placenta.

The goal of this study was to provide a representative description of the normal placenta with contrast medium-free magnetic resonance imaging (MRI) in order to determine a standard of reference. One hundred consecutive singleton pregnancies were investigated by MRI without application of a contrast medium. The mean gestational age (GA) at the time of investigation was 29.5 weeks (range 19-40). Patients with suspected utero-placental insufficiency (UPI) or placental anomalies were excluded. Signal intensities were assessed and correlated with the respective GA. Antenatal MRI without contrast medium was able to depict placental status and morphological changes during gestation. A regular homogeneous structure was found in weeks 19-23. Subsequently, sporadic, slightly marked lobules appeared, which increased in number and markedness with ongoing gestation. Stratification of the lobules was observed after 36 weeks. The ratio of placental and amniotic fluid signal intensities decreased significantly with higher GA and with placental grading. MRI is well suited as an imaging method for the placenta. Our data may be used as a reference in the assessment of the placenta on MRI, and may have further clinical impact with respect to the determination of UPI.

Female↗
PubMed2006

MRI of normal and pathological fetal lung development.

Normal fetal lung development is a complex process influenced by mechanical and many biochemical factors. In addition to ultrasound, fetal magnetic resonance imaging (MRI) constitutes a new method to investigate this process in vivo during the second and third trimester. The techniques of MRI volumetry, assessment of signal intensities, and MRI spectroscopy of the fetal lung have been used to analyze this process and have already been applied clinically to identify abnormal fetal lung growth. Particularly in conditions such as oligohydramnios and congenital diaphragmatic hernia (CDH), pulmonary hypoplasia may be the cause of neonatal death. A precise diagnosis and quantification of compromised fetal lung development may improve post- and perinatal management. The main events in fetal lung development are reviewed and MR volumetric data from 106 normal fetuses, as well as different examples of pathological lung growth, are provided.

Female↗
PubMed2006

Central diabetes insipidus: Is it Langerhans cell histiocytosis of the pituitary stalk? A diagnostic pitfall.

Central diabetes insipidus (CDI) is a rare disorder that may be caused by a variety of diseases. In pediatric and adolescent patients the most common causes for CDI are Langerhans cell histiocytosis (LCH) and germinoma. To avoid a potentially hazardous biopsy of the hypothalamic pituitary region it is recommended to evaluate patients with CDI carefully to identify potential extracranial lesions. Since LCH is the most common systemic disease that may cause CDI, special focus is paid to the identification of LCH lesions. We report on a 9(1/2) year old girl who presented with central diabetes insipidus and a thickening of the pituitary stalk on magnetic resonance imaging. Diagnostic workup revealed a history of recurrent ear infections and a compressed 6th thoracic vertebral body on radiographs. Based on these findings LCH was anticipated. Upon growth of the pituitary stalk lesion the patient was treated with LCH standard chemotherapy. After an initial shrinkage of the lesion, a further growth of the pituitary stalk lesion was observed and the tumor was resected. Histopathology revealed germinoma. This case underscores the importance of a istopathologically proven diagnosis in patients with HPR tumors before the initiation of a specific therapy, even if the clinical findings are highly suggestive.

Biopsy↗
PubMed2005

Methods of fetal MR: beyond T2-weighted imaging.

The present work reviews the basic methods of performing fetal magnetic resonance imaging (MRI). Since fetal MRI differs in many respects from a postnatal study, several factors have to be taken into account to achieve satisfying image quality. Image quality depends on adequate positioning of the pregnant woman in the magnet, use of appropriate coils and the selection of sequences. Ultrafast T2-weighted sequences are regarded as the mainstay of fetal MR-imaging. However, additional sequences, such as T1-weighted images, diffusion-weighted images, echoplanar imaging may provide further information, especially in extra- central-nervous system regions of the fetal body.

Female↗
PubMed2005

Magnetic resonance imaging in patients with obsessive-compulsive disorder with good versus poor insight.

The DSM-IV provides two subtypes of obsessive-compulsive disorder (OCD), labelled as OCD with insight and OCD with poor insight. For the latter, patients generally fail to recognize that the obsessions or compulsions are excessive or unreasonable. Several studies have shown significant brain abnormalities in OCD patients. However, at present, it remains unclear whether a specific pattern of structural brain abnormalities is related to poor insight in OCD. In the present study, magnetic resonance imaging (MRI) findings were compared in OCD patients with insight versus those with poor insight. Outpatients with diagnoses of OCD according to DSM-IV (300.30) and ICD-10 (F42) (n = 84; mean age 38+/-13; 35 females, 49 males) were dichotomized into the two subtypes. All subjects underwent an MRI examination. MRI findings were rated as "MRI abnormality" and "normal MRI." In our sample, 48% of the patients had MRI abnormalities. There was a highly significant difference between the two groups according to frequencies of MRI abnormalities, with 83% of the patients with poor insight showing MRI abnormalities compared with only 21% of the patients with insight. The specifier "poor insight" helps to identify a subgroup of OCD with a higher frequency of brain abnormalities of various types. This distinction should be taken into account in future studies concerning the course and therapeutic outcome of OCD.

Basal Ganglia↗
PubMed2005

Intraventricular meningiomas: a report of 16 cases.

Meningiomas of the ventricle system are extremely rare. We report on a series of 16 intraventricular meningiomas (IVMs) treated at our institution between 1980 and 2004, with a special interest on the surgical outcome of using the intra/inter-parietal and parieto-occipital approach and the benefits of neuro-navigation. A retrospective analysis of the medical files for clinicoradiological findings, surgical interventions and surgical outcome was carried out. In 16 IVM patients with a female/male ratio of 11:5, age ranged from 24 years to 84 years (median 44 years). Duration of symptoms ranged from a few days to several years, and the cardinal symptoms were signs of increased intracranial pressure (86%), followed by corticospinal tract signs (43%), visual field defects (36%), cognitive changes (29%) and seizures (7%). The majority of tumours was located in the trigone (88%), and one was found in each the temporal horn and in the fourth ventricle. Tumour size ranged from 2.5 cm to 8 cm (median 5 cm), and the radiological appearance was uniform. The neuropathological workup revealed most IVMs as meningothelial, transitional (mixed) or lymphoplasmacyte-rich meningiomas (81%). Three tumours were classified as atypical (19%) and the MIB-1 proliferation index ranged from 1% to 40%. Complete resection was possible in all but one case. The trigonal IVMs were resected via an intraparietal/inter-parietal or parieto-occipital approach, and neuro-navigation was used in eight tumours. We encountered one perioperative death and one severely disabled patient. All other patients had a Glasgow outcome scale score of 5, and most of the pre-existing symptoms disappeared or improved after surgery. IVMs are a surgically curable tumour entity in most cases. The intraparietal/inter-parietal and parieto-occipital approach is very safe, and neuro-navigation allows early devascularisation of the tumour.

Adult↗