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Biomedical subjects

G Wilms

Publications and source records attributed to G Wilms.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Colloid cysts of the third ventricle: MR findings.

Magnetic resonance was performed in five patients with obstructive hydrocephalus due to surgically proven colloid cyst of the third ventricle. On T1-weighted images two lesions were homogeneously hyperintense and another homogeneously isointense with the surrounding brain parenchyma. On T2-weighted images these three lesions were strongly hypointense except for a hyperintense rim at the periphery. At surgery in these patients the cyst was thin walled and filled with viscous colloidal material. In two patients the content of the lesion was composed of two layers. The outer layer was hyperintense and the inner layer hypointense in one patient. In the other patient the periphery of the lesion was isointense with central hypointensity. On T2-weighted images the content of both lesions was hyperintense at the periphery with central hypointensity. In these last two patients at surgery the cyst was thin walled too. However, two clearly different components could be found in the cyst content: an outer component composed of amorphous material and cellular debris and an inner component consisting of viscous material.

Adult↗
PubMedDate not supplied

Localized 1H NMR spectroscopy in fifty cases of newly diagnosed intracranial tumors.

Fifty patients with newly diagnosed, untreated intracranial tumors were examined with 1H nuclear magnetic resonance single-volume spectroscopy (MRS) using a 1.5 T whole-body MR system. Prior to the MRS, contrast enhanced MR and/or CT imaging studies were carried out. Histological verification was obtained in all patients except one. All tumor spectra revealed distinct abnormalities as compared with the normal brain spectra. Although most meningiomas showed a rather characteristic spectral pattern, generally features specific for the various tumor types were not observed. For instance, though a strong lactic acid signal was seen in most malignant tumors, this signal was also evident in five benign neoplasms.

Adult↗
PubMedDate not supplied

Gadolinium-enhanced MR imaging of cerebral venous angiomas with emphasis on their drainage.

Gadolinium-enhanced MR was performed in 28 patients with 17 supratentorial and 11 cerebellar venous angiomas. The use of gadolinium allowed detection of 9 of 28 venous angiomas (32%) that were not visible before gadolinium or which were only recognized in retrospect. Before gadolinium the peripheral medullary veins that are typical for these venous malformations were only visualized in 4 of 17 (23%) supratentorial and in 5 of 11 (45%) cerebellar lesions, for a total of 9 of 28 (32%) venous angiomas. After intravenous administration of gadolinium these veins were seen in 27 of 28 (96%) venous angiomas. Extension of the lesions to the wall of the ventricles was seen in 24 of the 28, 16 of 17 supratentorial and 8 of 11 cerebellar, lesions after gadolinium. This information was missed on plain MR in 6 of these lesions. The type of venous drainage, either superficial or deep, could be determined by gadolinium-enhanced MR in all cases where angiography was available for comparison. Before gadolinium this information was not available in eight patients. The intravenous administration of gadolinium adds significant information in the MR study of venous angioma.

Adult↗
PubMedDate not supplied

Axial vs sagittal T2-weighted brain MR images in the evaluation of multiple sclerosis.

Axial and sagittal proton density and T2-weighted MR images (TR 2,500-3,000 ms, TE 15-22 and 85-90 ms) were performed in 50 patients with multiple sclerosis (MS) on a 1.5 T superconductive system. The number of plaques on the axial and sagittal images in the periventricular white matter, the corpus callosum, the brain stem, the cerebellum, and the basal ganglia were counted separately by two independent observers. A total of 858 lesions (mean 17.40 +/- 21.57) were seen on the axial series and 1,196 (mean 24.32 +/- 26.22) on the sagittal scans. More lesions were visualized on sagittal images in the periventricular region (mean 18.79 +/- 21.69 versus 13.34 +/- 16.45; p less than 0.001) and the corpus callosum (mean 3.00 +/- 2.72 versus 0.57 +/- 1.19; p less than 0.001). In the brain stem more lesions were visualized on the axial images (mean 1.55 +/- 2.55 versus 0.87 +/- 1.20; p less than 0.05). In the cerebellum and basal ganglia, scans in the two planes were equivalent (p greater than 0.5). In three patients lesions were seen on the sagittal series, while the axial scans were normal. Sagittal T2-weighted images appear to demonstrate significantly more MS plaques than transverse images, especially in the periventricular region and the corpus callosum. This is explained by partial volume averaging, by the orientation of some cerebral structures (e.g., corpus callosum) with regard to the section plane, and by the longer diameter of the lesions in the axial plane.

Brain Diseases↗
PubMedDate not supplied

Sequences and techniques in spinal MR imaging.

The optimal protocol in spinal MR imaging is not evident. Sagittal T2 weighted FSE, sagittal T1 weighted SE and axial T2 weighted FSE sequences are widely accepted for imaging patients with sciatica and/or lumbar pain. Because of the limited amount of CSF compared to the lumbar spine, the choice of sequences is much more complex in the study of the cervical spine. Sagittal T2 FSE, sagittal T1 SE and axial 2D GE images are suggested in routine cervical spine imaging. To assess the bone marrow, a STIR sequence can be added to this protocol on both lumbar and cervical spine examinations. The 2D GE produces an acceptable image quality to differentiate between the disc and bony protrusions. The use of FLAIR for imaging spinal cord lesions remains controversial in the literature.

Cervical Vertebrae↗
PubMedDate not supplied

Non-traumatic giant aneurysm of a superficial temporal artery.

We present a case of giant aneurysm in the superficial temporal artery. A 59-year-old male was admitted to our hospital with a slowly growing swelling just in front of his right ear. Diagnosis was made by US and CT. CTA was able to provide accurate anatomic information and to eliminate the risks associated with diagnostic conventional angiography. A superselective embolization of the giant temporal aneurysm was performed.

Aneurysm↗
PubMedDate not supplied

Gyriform calcifications in tuberous sclerosis simulating the appearance of Sturge-Weber disease.

Two cases of tuberous sclerosis are presented. Extensive superficial occipital calcifications were found as classically described in Sturge-Weber syndrome. Other radiologic signs of tuberous sclerosis, such as subependymal calcifications in both patients and surgically proved giant cell astrocytoma in one patient, were present. At pathologic examination, the calcifications appeared to be located in extensive cortical tubers.

Brain Diseases↗
PubMedDate not supplied

Spurious absence of signal on 3D time-of-flight MR angiograms on 1 and 3 tesla magnets in cerebral arteries associated with a giant ophthalmic segment aneurysm: the need for alternative techniques.

There are many high-resolution MR angiographic techniques available today for the evaluation of circle of Willis. We report a case of bilateral aneurysms of the carotico-ophthalmic segment, the left one being a giant aneurysm, in a 41-year-old woman. She underwent different MRA sequences on both 1 and 3Tesla magnets and a digital subtraction angiography. 3D time-of-flight angiograms can give spurious information on giant aneurysms and other techniques like phase contrast and dynamic contrast enhanced angiographies can supplement if not replace it. High field strength improves the objective quality of MR angiograms, but in the case of large aneurysms, intra aneurysmal and distal vessel signal loss can be a significant problem.

Adult↗
PubMedDate not supplied

Prominent dural enhancement adjacent to nonmeningiomatous malignant lesions on contrast-enhanced MR images.

Prominent dural enhancement was noted in 10 (16%) of 61 superficial malignant intracranial tumors studied with contrast-enhanced MR imaging during a 2-year period. Included were six glioblastomas, three parenchymal metastases, and one case of dural metastasis. Seven patients had surgery. In four, there was extensive leptomeningeal invasion in the center of the lesion. In two of these lesions there was firm attachment of the center of the tumor to the dura, but without dural invasion despite extensive external carotid artery supply to the tumor in one case. In two cases the overlying dura was normal, and there was no leptomeningeal tumoral invasion. In the case of dural metastasis, huge nodular lesions were present along the inner aspect of the dura. In none of the cases did prominent dural enhancement adjacent to the tumor correspond with tumoral invasion or extension to the dura. Prominent dural enhancement on contrast-enhanced MR images appears to be much less frequent in malignant tumor than in meningioma, where it is seen in up to 60% of the cases. We believe this finding is more likely to represent reactive changes of the dura than tumoral invasion.

Brain Neoplasms↗
PubMedDate not supplied

Intracranial meningiomas: correlation between MR imaging and histology in fifty patients.

The magnetic resonance (MR) findings in 50 surgically verified intracranial meningiomas were reviewed. An attempt was made to correlate their signal intensity on spin echo (SE) T1-weighted, proton density [N(H)], and T2-weighted images with the different histologic subtypes. The T1-weighted images were nonspecific in differentiating the subtypes of meningiomas. On proton density and T2-weighted images, more information was available, but there remained large group (46%) of meningiomas that were not classifiable. The average signal intensity scores on T1-weighted, proton density, and T2-weighted images in the different histologic subtypes were correlated with each other using the Student t test. Only one significant correlation (psammomatous-anaplastic) and three almost significant correlations (syncytial-transitional or psammomatous and transitional-psammomatous) were found. Different histologic subtypes may have a different MR appearance, but this does not suffice to reach a histologic diagnosis by MR imaging.

Adult↗
PubMedDate not supplied

CT demonstration of aneurysms in polyarteritis nodosa.

The CT features in a case of polyarteritis nodosa are reported. Besides the classic cortical renal infarcts, it was possible to demonstrate on CT aneurysms of the renal and pancreatic arteries because of their rather large diameter. The combination of renal aneurysm and renal or splenic cortical infarcts should be considered highly suggestive for polyarteritis nodosa.

Adult↗