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Biomedical subjects

N Yünten

Publications and source records attributed to N Yünten.

12 recordsLinked to original sources
PubMed2004

Role of the constructive interference in steady-state sequence in the classification of sacral meningeal cysts.

PURPOSE: To investigate the role of the CISS (constructive interference in steady state) sequence in sacral meningeal cysts. MATERIAL AND METHODS: Fourteen patients with sacral meningeal cysts were included. Conventional T1W and T2W sequences and the CISS sequence (TR/TE = 12.25/5.90) were obtained at 1.5-T. The 1-mm-thick base images and multiplanar reformatted images of the CISS sequence were studied. The sacral meningeal cysts were classified by the CISS sequence in accordance with the previously described surgical and histopathological criteria. RESULTS: A total of 25 sacral meningeal cysts were identified in the 14 patients. The cysts and their contents were visualized by the CISS sequence, and the CISS sequence was superior to the T1W and T2W images. Fifteen of the cysts were consistent with type I lesions (extradural meningeal cysts without nerve fibers inside) and 10 cysts with type II lesions (extradural meningeal cysts with nerve fibers inside). There were no type III lesions (intradural meningeal cysts) in the sacral region. CONCLUSION: Previous studies have indicated that conventional MRI as well as magnetic resonance myelography are inconsistent for a classification of sacral meningeal cysts. The CISS sequence with its capability to obtain T2W thin slice acquisitions is superior in showing the nerve root fibers contained in the cysts, which is essential in the differentiation of type I and II cysts. Application of the CISS sequence is recommended in the diagnosis of sacral meningeal cysts.

Adult↗
PubMed2002

Diagnostic value of electrical stimulation of lumbosacral roots in lumbar spinal stenosis.

OBJECTIVES: This paper compares the diagnostic sensitivity of two tests in lumbar spinal stenosis (LSS): lumbosacral root stimulation with needle electrodes and needle electromyograph (EMG). MATERIAL AND METHODS: Twenty patients with LSS were assigned to two groups: Patients with 'neurogenic intermittent claudication' (NIC) only (n=11), and patients with 'neurological signs' (n=9). Ten normal subjects were also examined. The effects of direct stimulation of the lumbosacral roots and conventional EMG recorded from important muscles [rectus femoris (RF): L4, tibialis anterior (TA): L5, soleus muscle (SOL): S1], were compared with each other and correlated with their respective clinical findings and radiological images. RESULTS: Needle EMG and nerve conduction study revealed pathology in 15/20 patients, and electrical stimulation of the roots in 17/20 patients. Agreement in radiological findings with electrical stimulation of the roots and EMG was found in 12 patients. The other patients were harmonic with radiological findings either in EMG or in electrical stimulation of the roots. CONCLUSIONS: Electrical root stimulation revealed more abnormalities in patients with LSS in comparison with needle EMG. However, both methods seemed to complement each other to show additional pathology in a given patient.

Adult↗
PubMed2002

Proton MR spectroscopy in the diagnosis and differentiation of encephalitis from other mimicking lesions.

In this study, proton magnetic resonance spectroscopy (1H MRS) findings of encephalitis were reported. For comparison, other lesions mimicking encephalitis on conventional magnetic resonance (MR) imaging were included in the study. These lesions consisted of acute infarctions and low grade infiltrative gliomas. The 1H MRS findings of encephalitis and gliomas were almost the same whereas infarctions revealed high lactate levels differentiating the disorder from other two pathologies. The differentiation of encephalitis and gliomas based on MR findings could reliably made with short time follow up MR examinations where gliomas tend to grow in contrast to encephalitis which showed regression.

Adolescent↗
PubMed2001

Hemangioblastoma causing cervical neural foraminal widening.

We present the MRI findings in a case of a 24-year-old woman with spinal hemangioblastoma, causing neural foraminal widening by producing a dumbbell mass in the lower cervical region. Hemangioblastomas can very rarely present as an intradural extramedullary lesions and this case is another exceptional pathology which should be considered among the differential diagnosis of enlarged intervertebral foramen due to neoplastic processes.

Adult↗
PubMed1998

Cervical osseous changes associated with vertebral artery tortuosity.

Vertebral artery tortuosity causing neural foraminal widening is a well described abnormality that should not be confused with other causes of neural foraminal enlargement, particularly on conventional roentgenograms. We, hereby, describe CT features of another cervical osseous change due to the vertebral artery tortuosity, the so called "tubular shaped vertebral artery canal", which is embedded in the vertebral body instead of causing neural foramen enlargement. Catheter and MR angiographic studies have also been performed to confirm the vertebral artery tortuosity causing the osseous changes.

Adult↗
PubMed1997

Chondrosarcoma causing cervical neural foramen widening.

Various neoplastic, vascular, and developmental causes may lead to spinal neural foraminal widening, the most common causes of spinal dumbbell lesions being schwannomas and neurofibromas. Occasionally, some other slow-growing tumors may cause neural foraminal widening. We report an exceptional case of a low-grade spinal chondrosarcoma which apparently developed from a pre-existing osteochondroma in the neural arcus of C6. The lesion passed through the C5-C6 foramen, producing a dumbbell mass.

Adolescent↗
PubMed1996

Tuberculous radiculomyelitis as a complication of spondilodiscitis: MR demonstration.

We present the MRI features and follow-up results in a case of acute tuberculous (TB) radiculomyelitis adjacent to spondilodiscitis in the thoracic spine. Medullary involvement by tuberculosis originating by different mechanisms have been demonstrated in the recent literature. However, this rare complication accompanying TB spondilodiscitis has not been reported.

Adult↗
PubMedDate not supplied

Hypoplastic lumbar pedicle in association with conjoined nerve root MRI demonstration.

We report a case of aberrant hypoplastic pedicle of the fourth lumbar vertebra and ipsilateral conjoined nerve root. Ipsilateral retroisthmic laminar defect, dysplastic lamina and transverse process, enlargement of neural foramen, hypoplasia of superior and inferior articular facet were present as associated with other neural arch anomalies. The extent of these anomalies was well demonstrated by MR imaging.

Adult↗
PubMedDate not supplied

Associated brain abnormalities in patients with corpus callosum anomalies.

Forty-nine patients with corpus callosum (CC) anomalies were evaluated in terms of the clinical features and magnetic resonance imaging (MRI) findings. CC anomalies were classified as CC agenesis: 6 (12%), CC hypogenesis: 5 (10%), and CC hypoplasia: 38 (78%). In the CC hypoplasia group the mean value of the genu thickness of the CC was 0.29 +/- 0.1 cm, which was less than the normal value of the age-matched normal children (normal range: 0.6-1.2 cm). The associated brain abnormalities were in five distinct groups: gray matter abnormalities, white matter abnormalities, midline brain structure defects, cortical atrophy, and encephalomalacia. There was no uniformity for the clinical spectrum of CC anomalies. Microcephaly, developmental delay and seizures were the prominent findings in patients. The clinical features were more severe in cases with associated brain anomalies.

Abnormalities, Multiple↗