Search PubMed⌕ Search

Biomedical subjects

C Plets

Publications and source records attributed to C Plets.

103 records · Page 6Linked to original sources
PubMedDate not supplied

Thickening of dura surrounding meningiomas: MR features.

Thickening of the dura in continuity with a convexity meningioma was noted on T1-weighted magnetic resonance (MR) images in seven patients. In five cases the corresponding CT image of the lesions was typical of meningioma. In two other cases the CT image of the lesions was atypical, owing to cyst formation in one and extensive edema in the other. After intravenous injection of paramagnetic contrast medium in four patients, the thickened dura demonstrated contrast enhancement at a variable distance from the tumor. In three patients the thickened dura was confirmed surgically. Pathology, available in one case, showed the thickened dura to correspond to tumoral extension within or around the dura. Magnetic resonance demonstration of thickening of the dura in continuity with a mass at the cerebral convexity may prove to be of importance in the differentiation of atypical lesions on CT and MR, especially with lower field magnets. Moreover, it could provide useful information to the neurosurgeon for more complete resection of the tumor.

Aged↗
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

Multimedia E-mail systems for computer-assisted radiological communication.

In the film-based organization of communicating radiological results to the referring physician, the different media (text, images, graphics, voice) are separated. When using computer technology, multimedia reports containing links between these different media can be used. This changes the way radiological reports are generated, accessed, and possibly discussed. We performed experiments in a clinical setting using two different metaphors for communicating multimedia information. In the 'paper metaphor', labels in the report text are linked to annotations in selected images. In the 'slide presentation metaphor', annotated images are presented synchronously to a spoken report. With both systems additional interaction between radiologist and referring physician is supported using multimedia 'electronic mail'. The experiments indicate that multimedia does not only significantly increase the efficiency of information transfer, but also has the potential to make reporting itself more efficient. Given that the amount of image-related information keeps growing, multimedia links are a promising method to give efficient access to the most relevant information.

Computer Graphics↗
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

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 and MR in infants with pericerebral collections and macrocephaly: benign enlargement of the subarachnoid spaces versus subdural collections.

PURPOSE: To compare CT and MR in the differentiation of benign enlargement of the subarachnoid spaces and subdural collections in infants with macrocephaly. METHODS: MR was performed in 19 infants with macrocephaly, showing bifrontal enlargement of the subarachnoid spaces on CT. RESULTS: In 11 patients, a single fluid layer could be distinguished on MR of the pericerebral collections, suggesting benign enlargement of the subarachnoid spaces. In eight patients, two separate layers were clearly differentiated, an outer layer that was hyperintense on all sequences and an inner layer with the same intensity as the cerebrospinal fluid. This indicated the presence of subdural collections. These collections were mainly frontal in six and extended over the entire hemisphere in two patients. On CT, these separate lesions were seen only in three patients and missed in three others. In two final patients, CT findings were equivocal with evidence of membrane formation within the hypodense collections. In seven patients with a subdural collection, subdural-external drainage was performed. In three patients, the collection was hemorrhagic. The protein content of the fluid showed a mean of 1381.7 +/- 785.6 mg/dL. The MR and surgical findings of a subdural collection correlated with the absence of a family history of macrocrania, an age under 5 months, and acute clinical signs of vomiting, somnolence, and hypotonia. CONCLUSION: MR appears essential in the differential diagnosis between benign enlargement of the subarachnoid spaces and subdural collections in infants.

Brain Diseases↗