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Biomedical subjects

T Stadnik

Publications and source records attributed to T Stadnik.

At least 19 recordsLinked to original sources
PubMed2002

Extramedullary plasmacytoma of the cavernous sinus.

We present the case of an 80-year-old male with an history of multiple myeloma (MM) stage I with extramedullary plasmacytoma of the neck, diagnosed 18 months before and in complete remission after radiation therapy and melphalan-prednisone therapy. He was admitted with signs and symptoms characteristic for cavernous sinus syndrome, including diplopia, exophthalmia, ptosis and orbital pain. Magnetic resonance imaging showed a mass lesion in the cavernous sinus, consistent with relapsing extramedullary plasmacytoma. The patient received palliative radiation therapy and high dose dexamethasone, but treatment failed and the patient died. This case represents one of the few reports of extramedullary plasmacytoma of the cavernous sinus. The development of a clinical presentation of cavernous sinus syndrome in a patient with a history of MM or extramedullary plasmacytoma should raise the suspicion of a plasmacytic involvement of the cavernous sinus.

Aged↗
PubMed2001

Severe adverse reactions with contrast agents for magnetic resonance: clinical experience in 30,000 MR examinations.

We report on the frequency, manifestations and reactions to gadolinium contrast media in patients who underwent MR imaging at our institution between 1988 and 1998. During a 10-year period 30,000 patients received an intravenous injection of 0.1 mmol/kg gadoterate meglumine or gadopentetate dimeglumine for an MRI examination. When a reaction occurred a written report was made (the events were categorized into mild, moderate, and severe). In the period of 10 years we obtained three reports of moderate or severe reactions to the administration of gadolinium. This paper discusses the safety issues of intravenous contrast media in MR imaging, focusing on two gadolinium complexes, gadoterate meglumine, gadopentetate dimeglumine.

Adult↗
PubMed1999

Diffusion-weighted MRI in cyclosporin A neurotoxicity for the classification of cerebral edema.

Cyclosporin A, an immunosuppressive agent, is known to have neurotoxic effects, but until now, there has not been agreement on the underlying mechanism. Our report suggests, by using diffusion-weighted MRI, that the brain lesions caused by cyclosporin A, are probably related to vasogenic edema. This may explain the complete recovery of the lesions on imaging when cyclosporine therapy is stopped.

Adult↗
PubMed1999

Use of diffusion-weighted MR imaging in differential diagnosis between intracerebral necrotic tumors and cerebral abscesses.

The differential diagnosis between intracerebral necrotic tumors and cerebral abscesses is frequently impossible with conventional MR imaging. We report two cases of cerebral abscesses that showed high signal on diffusion-weighted echo planar imaging and a strongly reduced apparent diffusion coefficient. This appearance was not present in our cases of necrotic/cystic gliomas (eight cases) and necrotic metastases (two cases). We believe that diffusion-weighted MR imaging may be a diagnostic clue in cases of cerebral "ring-enhancing" masses.

Aged↗
PubMed1997

Calcified, cystic brain metastases.

Calcifications are uncommon in metastases. Adenocarcinoma, osteopenic, osteosarcoma, lung and breast carcinoma can be the origin. A rare case of calcified cystic brain metastasis deriving from papillary cystadenocarcinoma is reported.

Aged↗
PubMed1996

[Medical imaging and headache: choice of studies and their economic impact].

These past few years, new imaging technologies, very efficient but often quite expensive, have been developed. Within the context of budgetary restrictions, these progresses require a carefully planned strategy on the choice of investigations. Within the clinical environment of headaches, we have to discuss: conventional radiology (skill and cervical spine), cerebral CT scan, Magnetic Resonance Imaging and Angiography. These examinations are first discussed about their strong and weak aspects; then their indications are presented by pathology group. The related costs are analysed in terms of: health insurance rate, real production costs, consumption volume and total budgetary cost for Belgium. Based upon these data, concrete recommendations are proposed.

Brain Diseases↗
PubMed1995

Cortical stimulation for central neuropathic pain: 3-D surface MRI for easy determination of the motor cortex.

Motor cortex electric stimulation has been reported to be effective for the treatment of central post-stroke pain and trigeminal neuropathic pain. Five patients with pain due to injury of the trigeminal nerve and with abnormalities of facial sensibility, as well as two patients suffering of a post-stroke thalamic pain, were subjected to stimulation applied epidurally on the motor cortex. Quadripolar electrodes were implanted under local anaesthesia and the precise location of the motor cortex was determined on three-dimensional surface MRI the day prior to surgery. In our experience, correct topographic localization of the electrode on the motor cortex seems to be crucial to obtain pain reduction.

Adult↗
PubMed1994

The value of three-dimensional turbo-FLASH and spin-echo sequences in the detection of pituitary microadenomas following gadolinium administration.

Our purpose was the comparison of T1-weighted spin-echo (SE) and three-dimensional (3D) Turbo-fast low-angle shot (FLASH) (3DTFL) in detection of 14 pituitary microadenomas following intravenous gadolinium (Gd). 3DTFL represents an important improvement in the diagnosis of pituitary microadenomas. In two cases, the site of the tumour was correctly identified only by Gd-enhanced Turbo-FLASH. Nevertheless, in two other cases, the Gd-enhanced 3DTFL gave false negative (FN) results while the T1-weighted SE images enabled correct localisation. Replacement of T1-weighted SE by 3DTFL cannot therefore be advocated and use of both contrast-enhanced sequences offers the highest detection capability for microadenomas.

Adenoma↗
PubMed1994

Pituitary microadenomas: diagnosis with dynamic serial CT, conventional CT and T1-weighted MR imaging before and after injection of gadolinium.

PURPOSE: The few studies comparing CT and MR in the diagnosis of pituitary microadenomas give discordant results. This prospective study compares the value of dynamic serial CT (DSCT), conventional CT (CCT), pre-Gd T1-weighted spin echo (T1SE-Gd) and post-Gd T1-weighted SE (T1SE+Gd) in the detection of pituitary microadenomas. METHODS: The value of CT and MR was assessed in 17 cases, with the surgical confirmation as reference. The CTs and MRs were independently and blindly evaluated by two neuroradiologists. Because the finding at MR and/or CT influenced the selection of patients for surgery, the positive predictive value was calculated. The sensitivity calculation applies only for a specific group of postsurgical patients with positive CT and/or MR (marked with an asterisk for these reasons). RESULTS: In this study, the highest sensitivity* (88% and 82%, respectively, for observers I and II) was achieved by DSCT. The T1SE-Gd and T1SE+Gd (evaluated separately) were slightly inferior (sensitivity* of 76% for observer I). The combination of T1SE-Gd with T1SE+Gd improved the sensitivity* to 94% and 82% respectively, for observers I and II. There was also moderate improvement of sensitivity* by combination of DSCT with conventional CT (94% for observer I). CONCLUSION: These results suggest that rapid injection of a large amount of contrast conjointly with a fast scanning through the pituitary is crucial for the confident detection of microprolactinomas. Taking into account the similar results of the combination DSCT + CT and T1SE-Gd + T1SE+Gd in the detection of microprolactinomas, high field MRI is the first step modality in the evaluation of presumed hypophyseal hyperprolactinemia.

Adenoma↗
PubMed1994

A method for myelin fiber orientation mapping using diffusion-weighted MR images.

In the past, the anisotropic diffusion of water molecules in white matter in the brain has been correlated to the basic symmetry of the myelin fibers: water diffuses more readily along the fiber direction than perpendicular to it. As a consequence, diffusion sensitized magnetic resonance imaging can be expected to be useful for studying the fiber orientation. In this work, we present a method for exploiting this type of information to map the fiber orientations in the image plane. It makes use of three diffusion-weighted images with sensitizing gradients along x, y and u, an axis at 45 degrees with respect to x and y. The orientation information contained in these images is summarized in a single image representing the angle between the fiber direction and a fixed axis, making use of a cyclic color scale. The method is evaluated using computer simulations for a variety of diffusion weighting strengths and signal-to-noise ratios, tested on a phantom and illustrated on an in vivo example. An extension to the determination of the fiber orientation in three dimensions is also described.

Anisotropy↗
PubMed1994

Easy preoperative planning of deeply located brain lesions using external skin reference and 3-dimensional surface MRI.

Open skull surgery of deeply located intracerebral lesions requires precise determination of the treatment area in 3-dimensional (3-D) space. 3-D MRI can give important additional information in presurgical determination of the surgical approach to the target, taking into account highly functional brain areas and important vascular structures. The day before surgery, a grid composed of 9 tubings intersecting at 90 degrees at 1 cm intervals and filled with a CuSO4 solution is firmly attached to the skin of the patient's head in the presumed region of the craniotomy. A 3-D turbo-FLASH sequence is then performed in the sagittal plane after intravenous Gd-DOTA injection on a 1T Magneton. 3-D surface reconstruction of the cortical gyri and sulci is performed. Once the gyri are identified, the 3-D program is then implemented in order to perform a color display of the cortical veins and of the tumor boundaries. The surgical access is then chosen by the surgeon, taking into account highly functional areas. Finally, the boundaries of the tumor are projected on the cortex reconstruction and on the external reference placed on the skin. The entry place for surgery as well as the size of craniotomy are drawn on the skin and the tubed grid is removed. The accuracy of this method tested in 9 patients with deeply located brain tumors or arteriovenous malformations was very satisfactory.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗
PubMed1992

Contrast behavior between microadenoma and normal pituitary gland after gadolinium injection as a function of time at 1.5 T.

The behavior of contrast enhancement between a microadenoma and the normal pituitary gland after gadolinium injection was evaluated in 12 operatively confirmed cases using a repetitive sequence of four coronal T1-weighted spin echo series (T1 SE) (continuous acquisition, TR = 400 ms), followed by conventional coronal T1 SE (TR = 600 ms) and a three-dimensional fast low-angle shot sequence. The first and second acquisitions were useful with respect to delayed scans only in 3 cases (25%). Nevertheless, in these cases confident diagnosis could also be made on pre-contrast studies, which diminishes the real advantage of this finding. For a 1.5 T MRI unit we advocate starting with coronal T1 SE 30 s after a rapid injection of gadolinium.

Adenoma↗
PubMed1992

Spinal arachnoiditis mimicking a spinal cord tumor: a case report and review of the literature.

We report on an unusual case of idiopathic arachnoiditis mimicking a spinal cord tumor in a 50-year-old man with progressive paraparesis. The medical imaging work-up showed an enlarged terminal cone with adjacent cysts. Although there was no enhancement of the terminal cone or the surrounding structures, the diagnosis of spinal cord tumor was maintained and surgery was carried out. Exploration of the cauda equina and the tissue surrounding the terminal cone did not reveal a tumor. The patient improved dramatically after surgery but the symptoms recurred 1 year later. We review arachnoiditis, its pathology, and its treatment with special attention drawn to the primary form of spinal arachnoiditis.

Arachnoiditis↗
PubMed1992

Treatment of macroprolactinomas with the long-acting and repeatable form of bromocriptine: a report on 29 cases.

Twenty-nine patients with macroprolactinomas were treated by monthly intramuscular injections of the long-acting and repeatable form of bromocriptine (Parlodel-LAR) in doses ranging from 50-150 mg. They were divided into two groups: group I consisted of 22 patients who received Parlodel LAR before transsphenoidal adenomectomy; group II was composed of 7 patients with earlier neurosurgery and of 2 patients from group I not cured by transsphenoidal adenomectomy. Duration of therapy varied from 1-12 months, and a total of 104 injections was given. At nadir day, serum PRL levels were situated between less than 1% and 43% of pretreatment values. At day 28 after the first injection, serum PRL levels varied between less than 1% to 139% of initial values. No difference could be detected between the two groups regarding the percent of PRL inhibition. Long-term treatment with Parlodel-LAR resulted in a sustained inhibition of PRL secretion, except for 1 case. Resumption of menstrual cycles occurred in 4 out of 15 women and correction of hypogonadism in 4 out of 14 men. Amelioration of disturbed visual fields was recorded in 3 out of 8 patients. Diminution of the adenoma volume was radiologically documented in 14 out of 22 cases. Only few and mild side effects were recorded. One patient with partial adrenal deficiency suffered from a syncope, but this was prevented by hydrocortisone supplementation during the subsequent Parlodel-LAR administration. In conclusion, Parlodel-LAR proved effective in the treatment of macroprolactinomas, achieving rapid inhibition of PRL secretion, and in some patients amelioration of hypopituitarism, reduction in tumor size, and improvement in visual fields, and caused no serious side effects. It is a valuable preparation to surgery and can also be used in long-term medical therapy.

Adult↗
PubMed1992

CT and MR findings in ruptured dermoid cyst in the right parasellar cistern: report of a case.

A case of ruptured dermoid cyst in the right parasellar cistern imaged by MRI and CT is reported. The disseminated lipid droplets were found scattered throughout the subarachnoid spaces including the prepontine cisterns, in front of the right petrous apex as well as bilaterally in the frontal horns. The density of the lipid droplets was comprised between -80 and -100 HU. The lesions were hyperintense on T1-weighted images and hypointense on T2-weighted images.

Adult↗