Biomedical subjects

D Prayer

Publications and source records attributed to D Prayer.

At least 19 recordsLinked to original sources

PubMed2006

[MRI of the fetal abdomen].

Magnetic resonance imaging (MRI) is an important diagnostic component for central nervous system and thoracic diseases during fetal development. Although ultrasound remains the method of choice for observing the fetus during pregnancy, fetal MRI is being increasingly used as an additional technique for the accurate diagnosis of abdominal diseases. Recent publications confirm the value of MRI in the diagnosis of fetal gastrointestinal tract and urogenital system diseases. The following report provides an overview of MRI-examination techniques for the most frequent diseases of the abdomen.

Abdomen↗

PubMed2006

[Indications for fetal magnetic resonance imaging].

Indications to perform fetal magnetic resonance imaging (MRI) are composed of common ones related to methodological problems of ultrasound (US) assessment (such as for instance hydramnios) and special ones. The latter are related to MR capability of high-resolution soft tissue contrast and an extended field of view that allows visualization of the whole fetus, even in later stages of pregnancy. The most important indications include confirmation of US findings, work-up of malformations with respect to individual prognosis and genetic background, differentiation between acquired conditions and malformations, visualization of pathologies that have to be treated surgically immediately after birth, and morphological changes of the placenta.

Congenital Abnormalities↗

PubMed2006

[Fetal MRI of pathological brain development].

Because of the superior tissue contrast, high spatial resolution, and multiplanar capabilities, fetal magnetic resonance imaging (MRI) can depict fetal brain pathologies with high accuracy. Pathological fetal brain development may result from malformations or acquired conditions. Differentiation of these etiologies is important with respect to managing the actual pregnancy or counseling future pregnancies. As a widened ventricular system is a common hallmark of both maldevelopment and acquired conditions, it may cause problems in the differential diagnosis. Fetal MRI can provide detailed morphological information, which allows refinement of the diagnosis of ventricular enlargement in a large number of cases. Systematic work-up of morphological details that may be recognized on MR images provides an approach for achieving a correct diagnosis in cases of ventricle enlargement.

Brain↗

PubMed2006

[Fetal magnetic resonance imaging: methods and techniques].

Since the introduction of fetal magnetic resonance imaging (MRI) into prenatal diagnostics, advances in coil technology and development of ultrafast sequences have further enhanced this technique. At present numerous sequences are available to visualize the whole fetus with high resolution and image quality, even in late stages of pregnancy. Taking into consideration the special circumstances of examination and adjusting sequence parameters to gestational age, fetal anatomy can be accurately depicted. The variety of sequences also allows further characterization of fetal tissues and pathologies. Fetal MRI not only supplies additional information to routine ultrasound studies, but also reveals fetal morphology and pathology in a way hitherto not possible.

Fetal Diseases↗

PubMed2006

[Fetal lung development on MRT. Normal course and impairment due to premature rupture of membranes].

A well-organized interplay between many molecular factors as well as mechanical forces influence fetal lung development. At the end of this complex process a sufficiently sized and structurally mature organ should ensure the postnatal survival of the newborn. Besides prenatal ultrasonography, magnetic resonance imaging (MRI) can now be used to investigate normal and pathological human lung growth in utero. Oligohydramnios, due to premature rupture of membranes (PROM), is an important risk factor for compromised fetal lung growth. In these situations MR volumetry can be used to measure the size of the fetal lung quite accurately. Together with the evaluation of lung signal intensities on T2-weighted sequences, fetuses with pulmonary hypoplasia can be readily detected.

Extraembryonic Membranes↗

PubMed2005

The clinical impact of magnetic resonance imaging in fetuses with central nervous system anomalies on ultrasound scan.

OBJECTIVES: Magnetic resonance imaging (MRI) was performed on fetuses with sonographically diagnosed central nervous system (CNS) anomalies to determine frequency and type of cases in which fetal MRI adds clinically relevant information. PATIENTS AND METHODS: Forty-three cases presenting with CNS anomalies by ultrasonography were investigated by MRI. The potential effect of MRI on parental counseling and pre- or postnatal management were the main endpoints. RESULTS: Fetal MRI confirmed the sonographic diagnosis in 28 of 43 cases, showed additional findings in 14 of 43 cases, and was inferior to sonography in 1 of 43 cases. The MRI diagnosis had therapeutic consequences in 11 of 43 patients, with the fetal MRI diagnosis influencing parental counseling in 8 of these 11 patients. Prenatal patient care was not influenced by the additional investigation with fetal MRI. CONCLUSION: MRI is well suited as additional imaging method in fetuses with CNS anomalies. Additional fetal MRI is particularly indicated if the findings might have a therapeutic consequence.

Adult↗

PubMed2005

Prenatal magnetic resonance imaging as a useful adjunctive to ultrasound-enhanced diagnosis in case of a giant foetal tumour of the neck.

Large cervical masses in the prenatal period are rare and can cause life threatening situations after birth. All available diagnostic techniques should therefore be used to determine the best mode of delivery in the case of such malformation. A large cervical mass was detected by ultrasound in a 41-year-old women, gravida 4, para 3, at 29 + 5 weeks of gestation. US imaging was most consistent with the diagnosis of a large cervical teratoma, but it was not possible to sufficiently evaluate the cervical anatomy of the oropharynx and trachea. An MRI scan demonstrated a distorted oropharynx and a trachea displaced to the right and posteriorly, but not detectable from the middle of the neck up to the larynx. Based on these facts, an EXIT procedure was planned and performed at 30 + 5 weeks of gestation. Foetal MRI provided valuable anatomical information for all specialists deciding on the indication and the pre-therapeutic planning of the EXIT procedure.

Adult↗

PubMed2005

Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC). Report of a new case.

Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) syndrome is a new neurodegenerative entity, which was first described by van der Knaap in 2002 in 7 patients aged from 2 months to 2 years. We describe a new, 42-month-old female patient who developed progressive dystonia, spasticity and oculogyric eye movements since the age of 3 months. The diagnosis was made by characteristic MRI findings including supratentorial hypomyelination and progressive atrophy of basal ganglia and cerebellum. Oculogyric eye movements have not been described in patients with H-ABC syndrome before. When compared with the normal age-related myelination patterns, the degree of hypomyelination increased progressively over the time course of 32 months, indicating arrest but not loss of myelination. The H-ABC syndrome adds to the differential diagnosis of progressive pyramidal and extrapyramidal movement disorders and to the increasing number of genetically determined hypomyelination syndromes.

Atrophy↗

PubMed2004

Recurrent spinal ependymoma showing partial remission under Imatimib.

BACKGROUND: There are few treatment options for recurrent spinal ependymoma after surgery and radiation therapy. CLINICAL PRESENTATION: We present a patient with recurrent spinal ependymoma who received radiation therapy after laminectomy and partial tumor resection. Months later, the patient developed gait paresis. MRT showed tumor recurrence and partial resection was again performed. Oral cytotoxic chemotherapy with Temozolomide was initiated. After a short relief, there was clinical worsening and MRT showed progressive disease. As the tumor had stained positively for platelet derived growth factor (PDGF) receptor, treatment with Imatimib was initiated. FINDINGS: The patient experienced improvement in neurological symptoms and the following MRT revealed slight tumor regression. She remained stable for a total of 11 months. CONCLUSION: Imatimib should be considered a potential therapeutic option in recurrent ependymomas expressing PDGF receptor.

Adult↗

PubMed2004

Vestibular processing in human paramedian precuneus as shown by electrical cortical stimulation.

The authors describe a 16-year-old patient with recurrent episodes of epileptic linear self-motion perception and occasional body tilts. Intracranial seizure monitoring located the seizure onset, caused by a circumscribed ependymoma, in the right paramedian precuneus. Electrical cortical stimulation of this area could reproduce the same vestibular sensations, which ceased after lesionectomy. The findings implicate the paramedian area of the precuneus in the processing of static and dynamic vestibular, probably otolithic, information.

Adolescent↗

PubMed2004

Brain abscesses after Serratia marcescens infection on a neonatal intensive care unit: differences on serial imaging.

Serratia are known to be a possible cause of severe cerebral infections in neonates. We describe imaging of three premature infants infected with Serratia marcescens. Born in the 31( st), 25( th) and 28( th) weeks of gestation, they presented with signs of septicaemia on postnatal days 9, 24 and 32. Initial sonography showed cysts in the first child, two areas with anechoic centre and echogenic rim in the second, and several echogenic areas in the third. Lesions were seen on CT, of low density in two cases and minimally increased density in the third. MRI in the first patient showed cysts with incomplete contrast enhancement of the lesions, while patient 2 showed five ring-enhancing fluid-containing lesions with thick walls. In the third patient two abscesses with contrast enhancement and several high-signal spots were seen. We discuss the pathophysiology of the lesions and the impact of the various imaging methods.

Brain Abscess↗

PubMed2004

Pineal gland abnormalities in Langerhans cell histiocytosis.

BACKGROUND: The most common types of central nervous system (CNS) disease in Langerhans cell histiocytosis (LCH) comprise involvement of the hypothalamic-pituitary region (HPR) and neurodegenerative changes in the cerebellum, basal ganglia or pons. In the review process of magnetic resonance images (MRI) from 129 LCH patients a high frequency of cysts within or large pineal glands was noted by chance. PROCEDURE: To prove whether this observation was specific for LCH or not, we compared MRI findings of the HPR in LCH patients with a control group of 55 non-LCH patients with the same age and sex distribution. RESULTS: In LCH patients, the pineal gland was significantly larger and also the number of pineal cysts was significantly higher as compared to the control group. No difference was found regarding the size or frequency of cystic changes between patients who had received chemotherapy prior to the MRI and untreated patients. In the LCH patients, we further found a significant correlation of pineal gland enlargement with involvement of the HPR, but not with neurodegenerative changes. Analysis of melatonin (the principal hormone of the pineal gland) levels in 24 hr urine in 14 LCH patients did not reveal a melatonin deficiency or overproduction in the LCH group as compared to 6 normal controls. CONCLUSIONS: The pineal gland is another site of possible CNS involvement in LCH. LCH CNS patients did not show an overt disturbance in melatonin levels. The role of the pineal gland in CNS LCH remains to be defined.

Adolescent↗

PubMed2004

Fetal skeletal deformities - the diagnostic accuracy of prenatal ultrasonography and fetal magnetic resonance imaging.

OBJECTIVE: To evaluate the diagnostic accuracy of prenatal ultrasonography and fetal magnetic resonance imaging (MRI) in fetuses with skeletal deformities (SD). METHODS: Fourteen pregnant women of 21 - 34 weeks of gestation whose fetuses had SD on prenatal ultrasound (seven fetuses with spina bifida, four with complex malformation syndrome, two with scoliosis, and one with chondrodysplasia) were additionally investigated by fetal MRI using a 1.5T superconducting system with T1-and T2-weighted sequences in three section-planes. Main outcome measures were diagnostic accuracy, potential effect on parental counselling and influence on perinatal management of the additional investigation with fetal MRI. RESULTS: In 10 cases ultrasound had a better diagnostic accuracy than MRI concerning the diagnosis of SD. In four cases with spina bifida MRI provided additional information towards preoperative evaluation for neurosurgery. In five cases parental counselling was improved. There was no influence on perinatal management. CONCLUSION: MRI may provide additional information to ultrasound scan in fetuses with spina bifida and consecutive neurosurgery; in fetuses with other skeletal deformities additional information may be expected only in rare cases.

Adult↗

PubMed2003

Fetal liver magnetic resonance imaging in anterior body wall defects: a study of specimens from the museum of pathology.

PURPOSE: The purpose of the study was to evaluate the appearance of liver anatomy in fetuses with complex anterior body wall defects (ABWD) using magnetic resonance imaging (MRI). METHODS: Nineteen specimens from the National Museum of Pathological Anatomy (Vienna) with a wide range of ABWD were studied on a 1.5-T MR scanner (T1- and T2-weighted sequences) with special focus on the liver and the relationship between the large lesion and the adjacent structures. RESULTS: The contrast of T2-weighted sequences was superior to that of the T1-weighted images. The liver was found in an intraabdominal location in 3 cases and in a completely extraabdominal location in 11 fetuses. Five fetuses had a very special configuration or position of the liver. Furthermore, the images showed an anteriorly located confluence of hepatic veins into the inferior vena cava in 5 specimens. Associated malformations of the complexly structured malformations involved the urogenital tract, the central nervous system (CNS), the cardiac system and the musculoskeletal system. Prenatal fast magnetic resonance imaging (MRI) in one fetus confirmed the liver in a both inside/outside position, whereas the diagnosis at fetal ultrasound scan (US) in this case had been uncertain. CONCLUSIONS: These results show that MRI may play an important part in antenatal diagnosis of ABWD, complementary to prenatal US. Prenatal fast MRI should be considered if fetal US yields ambiguous findings.

Abdominal Wall↗

PubMed2003

Glatiramer acetate treatment in patients with childhood and juvenile onset multiple sclerosis.

BACKGROUND: Recent data indicate that in multiple sclerosis disease onset before the age of 16 is more common than previously assumed. However, current therapeutic options are limited to the treatment of acute attacks in these patients. Glatiramer acetate has been successfully applied in adults with relapsing-remitting multiple sclerosis, but there are no data available about the use of glatiramer acetate in childhood and juvenile onset multiple sclerosis. METHODS: Seven patients with relapsing-remitting multiple sclerosis and disease onset between 9 and 16 years of age were treated with daily subcutaneous injection of 20 mg glatiramer acetate (Copaxone). Patients were followed for 24 months. Treatment was initiated in all patients before the age of 18. RESULTS: The use of glatiramer acetate in our cohort of early onset multiple sclerosis patients was safe and well tolerated. Two out of seven patients remained relapse-free during the two year period. Clinical disability as measured by the EDSS remained stable in three out of seven patients. CONCLUSION: Due to the small number of patients the efficacy of the treatment has to be interpreted with caution. However, there might be a more pronounced treatment benefit in patients with low disability at treatment initiation and early treatment onset.

Adjuvants, Immunologic↗

PubMed2003

Degree of hypomyelination and magnetic resonance spectroscopy findings in patients with Pelizaeus Merzbacher phenotype.

As only 10 - 30 % of patients with a Pelizaeus Merzbacher disease (PMD) phenotype carry mutations of the proteolipid protein (PLP) gene, we were interested if the degree and time-dependent progression of abnormal MRI and MRS findings would discriminate patients with mutations of the PLP gene (Pelizaeus Merzbacher disease, PMD) from patients without a defect of the PLP gene (Pelizaeus Merzbacher-like disease, PMLD). For a standardised intraindividual follow-up and for comparison of the degree of hypomyelination, we have applied a newly developed semiquantitative myelination score on a total of 18 MRI series of 4 PMD and 4 PMLD patients. We found severe hypomyelination (< 50 % of normal) in 2 PMD and in 2 PMLD patients, moderate hypomyelination (< 75 % of normal) in 2 PMD and mild hypomyelination (> 75 % of normal) in 2 PMLD patients. Our score revealed a clear correlation between the degree of hypomyelination and the severity of clinical handicap in PMD but not in PMLD patients. MRS showed heterogeneous cerebral metabolite patterns in both patient groups and seems to reflect a mixture of unspecific changes due to primary hypomyelination and secondary gliosis and demyelination. Neither by MRI nor by MRS were patterns found that would allow differentiation between PMD and PMLD patients.

Adolescent↗

PubMed2002

Sequential MRI in a case of Creutzfeldt-Jakob disease.

A 48-year-old man suddenly developed clinically and electroencephalographically nonspecific dementia. On MRI sequences, only diffusion-weighted images (DWI) of the cortex were unequivocally pathological. Obvious atrophy and basal ganglia signal changes appeared only 9 months after the onset. Brain biopsy confirmed Creutzfeldt-Jakob disease (CJD). In rapidly progressive dementia, we recommend DWI for early diagnosis of CJD.

Brain↗

PubMed2002

Effects of oral creatine supplementation in a patient with MELAS phenotype and associated nephropathy.

An 18-year-old male patient with MELAS phenotype and 2 previous episodes of cerebral stroke, recurrent seizures and nephropathy, was treated with creatine monohydrate after the acute onset of psychomental regression and changing states of somnolence and aggressive and agitated behaviour. These symptoms disappeared completely after 4 weeks of treatment with creatine after which the patient regained all his previous mental abilites. Brain (white matter) proton magnetic resonance spectroscopy (chemical shift imaging) performed at 6 and 12 months of treatment showed lactic acid (Lac) accumulation and high creatine (Cr) levels in relation to choline-containing compounds (Cho). Urinary creatinine excretion as an indicator of the muscle and brain creatine pool increased upon short-term (12 days) high-dosage creatine supplementation (20 g per day) while plasma creatinine concentrations as possible indicators both of increasing creatine pool and of renal insufficiency increased during the course (28 months) of low-dosage creatine supplementation (5 g per day). Deterioration of renal function was finally indicated by urea retention and by impairment of renal creatinine clearance. These observations suggest that creatine supplementation may have a neuroprotective effect in patients with MELAS and episodes of acute mental deterioration. Adverse effects of creatine supplementation on renal function must be considered especially in patients with preexisting nephropathy.

Administration, Oral↗