Search PubMed⌕ Search

Biomedical subjects

J L Dietemann

Publications and source records attributed to J L Dietemann.

At least 19 recordsLinked to original sources
PubMed2001

Myocardial flow reserve parametric map, assessed by first-pass MRI compartmental analysis at the chronic stage of infarction.

Regional myocardial flow and flow reserve (MFR) were assessed by compartmental analysis of Gd-enhanced MRI first-pass data in 7 patients with atypical chest pain, and in 15 patients with previous transmural myocardial infarction. The FE product (Flow x Extraction coefficient), derived from the modified Kety equation, was measured in regions corresponding to the Tetrofosmine-SPECT fixed defect and in remote normal regions. The FE product at rest and hyperemic FE product were similar in healed revascularized tissues (70.5 +/- 15.6 and 112.5 +/- 19.5 ml/mn/100 g, respectively) and in normal myocardium (76.2 +/- 18.3 and 142.2 +/- 33.0, respectively). In contrast, the FE index (48.8 +/- 15.2 and 60.7 +/- 18.0, respectively, P < 0.01 versus the two previous groups) and the MFR (1.27 +/- 0.20 vs. 1.91 +/- 0.29 in normal regions) were reduced in healed fibrotic tissues when the infarct-related artery remained occluded. Myocardial flow reserve maps allowed correct identification of regions corresponding to an occluded infarct-related artery.

Aged↗
PubMed2001

A case of multiple sclerosis triggered by organic solvents.

The neurotoxicity of organic solvents has long been recognized. Some are used as anesthetic agents, others in various industries. Their acute effect has been well documented since the nineteenth century, but more recently they have become notorious as the cause of addiction to glue sniffing. They may alter the immune system by causing lymphopenia, impairing phagocytosis and decreasing the level of serum complement, as well as altering the impermeability of the blood-brain barrier and leading to the appearance of white matter lesions in the brain. The following case study explores the possible role of organic solvents in the pathogenesis of multiple sclerosis.

Central Nervous System↗
PubMed2000

MRI in multiple sclerosis of the spinal cord: evaluation of fast short-tan inversion-recovery and spin-echo sequences.

We compared the sensitivity of T2-weighted spin-echo (FSE) and fast short-tau inversion-recovery (fSTIR) sequences in detection of multiple sclerosis of the spinal cord in 100 consecutive patients with clinically confirmed multiple sclerosis (MS); 86 patients underwent also brain MRI. In all, 310 focal lesions were detected on fSTIR and 212 on T2-weighted FSE, spinal cord lesions were seen better on fSTIR images, with a higher contrast between the lesion and the normal spinal cord. In 24 patients in whom cord plaques were shown with both sequences, the cranial study was normal or inconclusive. Assessment of spinal plaques can be particularly important when MRI of the brain is inconclusive, and in there situations fSTIR can be helpful.

Adult↗
PubMed2000

Factors associated to hypermanganesemia in patients receiving home parenteral nutrition.

BACKGROUND: Home parenteral nutrition (HPN) patients often present hypermanganesamia. AIM: To examine which factors may be associated to hypermanganesemia in HPN patients. METHODS: Plasma manganese (Mn), liver function tests, C-reactive protein concentrations, erythrocyte sedimentation rate (ESR), tumor necrosis factor-alpha (TNF- alpha), interleukin-6, soluble receptors of interleukin-2, and blood neopterin concentrations were determined in 21 HPN patients and 10 healthy controls. Brain magnetic resonance imaging (MRI) and careful neurologic clinical examination were performed in 11 patients. RESULTS: Mn concentration was higher in HPN patients than controls (1.96+/-1.1 vs 0.81+/- 0.4 microg/L;P<0.001) and positively correlated to the amount of parenteral nutrition (PN) supply, transaminases and alkaline phosphatase (r=0.53, P<0.0001) concentrations, as well as to ESR (r=0.61, P<0.0001), TNF- alpha and blood neopterin. The amount of calories provided by PN was positively correlated to inflammatory markers and liver parameters. All patients investigated by MRI showed hyperintense basal ganglia on T1-weighted images suggesting brain Mn deposition. Only one had slight clinical extrapyramidal symptoms. CONCLUSION: In HPN patients, sustained inflammation may facilitate hypermanganesemia through 1. cholestatic liver disease and thereby decreased Mn biliary excretion, 2. high nutritional requirements (responsible for increased Mn supply), and/or 3. modified Mn metabolism or body distribution. Neurologic complications appeared marginal whereas Mn brain deposition seems frequent.

Adult↗
PubMed2000

[Cartography of absolute myocardial perfusion with magnetic resonance imaging. Methods and results].

Ultra-rapid dynamic MRI (one image per heart beat) can follow the progression of the intra-myocardial signal during the first passage of diffusable gadolinium chelates injected as a bolus through a peripheral vein. A quantitative evaluation of myocardial perfusion is possible using a compartmental model of analysis. Absolute myocardial flow can be measured at rest and during hyperaemia induced by dipyridamole. It is possible to associate functional mapping, corresponding to parametric images of the flow indices, to the global evaluation. The ratio between the values obtained during hyperaemia and under basal conditions correspond to the myocardial reserve. The principles, results and limitations of this method are discussed in the light of published results, underlining the advantages of absolute flow measurement and of the differences between the results of MRI and myocardial scintigraphy.

Coronary Circulation↗
PubMed2000

[Aspects of FLAIR sequences, 3D-CISS and diffusion-weight MR imaging of intracranial epidermoid cysts].

We propose to assess the usefulness of diffusion-weighted MR Imaging (DWI), fluid-attenuated inversion recovery (FLAIR) and constructive interference in steady state (CISS) sequences in depicting epidermoid cysts (EC). FLAIR, CISS and DWI were obtained in 7 patients among 22. All patients were studied with T1 and T2 sequences. On Spin Echo images, EC demonstrate signal similar to LCS, which may lead to difficult differentiation between EC and arachnoid cyst (AC), specially for inexperienced radiologists. EC appear with a heterogeneous signal on T1 images (32%), irregular limits (91%) and with extension through foramen of Pacchioni in 18% of cases. On FLAIR sequence, the tumors were heterogeneous, different from void signal of CSF in 86% of cases. On CISS sequence, the tumors appear heterogeneous, hyperintense but less than LCS and with irregular limits in all cases. Some more, CISS images allowed to appreciate exact tumor extension and their relations with nerves and vessels. On DWI images, signal is hyperintense in all cases. Our study exhibited the great usefulness of DWI, CISS and FLAIR sequences in diagnosis of EC and in differentiating EC from AC.

Brain Diseases↗
PubMed2000

[Acute disulfiram intoxication with severe neurological sequaelae and presenting misleading psychiatric deficiency].

Disulfiram self poisoning is exceptional. The authors report on the case of such an intoxication related to the ingestion of a potentially lethal dose of this drug (30 g) and draw the attention on the following points: 1) The initial signs may be misleading because they include both psychiatrics and neurological signs such as phonation abnormalities, myoclonias and tetraparesia. 2) The evolution is unforseeable with the possible occurrence of severe psychological and motricity sequaelae, associated with bilateral and symetric injuries of the putamen, the palladium and the basal nuclei on CT-scan (or MRI). The pathophysiologic al mechanisms of theses signs are discussed, and the need for disulfiram in the care of alcoholic patients seeking for withdrawal as well.

Adult↗
PubMed2000

[Spontaneous regression of an acute spinal subdural hematoma. MR imaging].

We report a case of acute spinal subdural hematoma which developed then regressed spontaneously. MR imaging contributed essential information for diagnosis and follow-up after conservative treatment. We made a short review of the literature and discuss the causes, pathogenesis, clinical presentation and usual treatment of acute spinal subdural hematoma. The differential diagnosis with the more frequent and extradural hematoma requiring immediate surgical evacuation is fundamental.

Aged↗
PubMed2000

[Contribution of 3D CISS MRI for pre- and post-therapeutic monitoring of obstructive hydrocephalus].

This report describes the use of the recent three-dimensional Fourier transform constructing imaging in the steady state (CISS) MR sequence in the management of obstructive hydrocephalus. It is a gradient-echo imaging technique with high resolution which remains sensitive to flow. It enables locating the obstruction and determining the upstream impact. It provides anatomical information about third ventricle (V3) morphology and relationships useful before ventriculostomy. Twenty patients with obstructive hydrocephalus at the level of cerebral aqueduct or posterior V3 underwent sagittal 3DFT-CISS acquisition, supplemented by frontal, axial and coronal reformations in the cerebral aqueduct axis. 9 patients were examined after ventriculostomy with the same protocol. CISS-3DFT allows good visualization of the cerebral aqueduct and diagnosis of the underlying cause of obstruction (malformation, tumor), sometimes better than classical sequences. In case of complete obstruction, the flow-related signal void is usually absent in the cerebral aqueduct or V3. The position of V3 floor and its relationship with the tip of basilar artery are well analyzed. The dilatation of the anterior V3 recesses is a better sign of activity of hydrocephalus - and then of therapeutical indication - than classical transependymal resorption signs which are not always present in chronic longstanding adult hydrocephalus. Of the 9 ventriculostomy patients seven had linear flow-related signal void through V3 floor, from anterior V3 to basal cisterns on the postoperative MR study. This flow void confirms patent ventriculostomy.

Adolescent↗
PubMed1999

Posterior extradural migration of extruded thoracic and lumbar disc fragments: role of MRI.

We report three patients with a sequestrated disc fragment posterior to the thecal sac. The affected disc was lumbar in two cases and thoracic in the third. Disc fragment migration is usually limited to the anterior extra dural space. Migration of a disc fragment behind the dural sac is seldom encountered. MRI appears to be the method of choice to make this diagnosis. The disc fragments gave low signal on T1- and slightly high signal on T2-weighted images and showed rim contrast enhancement. The differential diagnosis includes abscess, metastatic tumour and haematoma.

Diagnosis, Differential↗
PubMed1999

Sphenoidal sinus mucocele after transsphenoidal surgery for acromegaly.

This report concerns one case of a sphenoid sinus mucocele occurring 17 years after transsphenoidal surgery for acromegaly. In 1979, a 51-year-old man was successfully operated by the transnasal transsphenoidal approach for a growth hormone (GH) adenoma 1 cm in diameter. In 1996, the patient was hospitalized for headaches and diplopia. He presented a loss of right visual acuity with paralysis of the right oculomotor nerve. The basal GH level was normal with a satisfactory decrease after oral glucose ingestion. Pituitary sellar radiography showed a disappearance of the posterior clinoid while magnetic resonance imaging revealed the existence of a bilocular, circular, homogeneous lesion of the sphenoid sinus 3 cm in diameter with a posterior and lateral extension. The diagnosis of mucocele was confirmed by surgical treatment, allowing drainage of the mucocele through a transsphenoidal approach. The drained material was composed of sinus epithelium containing many polynuclear and resorptive cells. Postoperatively, the symptoms decreased dramatically, leading to full recovery of visual function and disappearance of the headaches. Apart from the tumor recurrence, the mucocele of the sphenoid sinus can be evoked as a possible long term complication of transsphenoidal surgery for pituitary adenoma.

Acromegaly↗
PubMed1999

Home parenteral nutrition: clinical and laboratory analysis of initial experience (1994-1997). Implications for patient management.

UNLABELLED: BACKGROUND/AIM AND METHOD: Severe malabsorption often necessitates prolonged parenteral nutrition. Home parenteral nutrition (HPN) offers the opportunity for treatment at home. We report clinical and laboratory data of initial 27 HPN patients of one center since its opening in 1994. RESULTS: Clinical and biological markers of nutritional status were normalized and well maintained in most patients. Except for vitamin E and selenium (lower in HPN patients), the other vitamin and micronutrient levels were normal. There was no obvious essential fatty acid deficiency. Cholestasis was usual, but only 1 patient had a severe hepatic disease. Catheter infection occurred 18 times in 13 patients, but the frequency decreased with time (from 4.2 to 1.7 infections/1,000 days on HPN). No patient died from HPN complications. Social rehabilitation and, in some patients, full professional rehabilitation were constant. CONCLUSIONS: These data confirm that HPN performed in centers with expertise allowed patients to overcome gut failure and to recover subnormal or normal nutritional status. Satisfactory social rehabilitation was obtained in all patients. HPN complications were rarely life-threatening, and their frequency decreased with experience.

Aged↗
PubMed1998

Is there a dural wall between the cavernous sinus and the pituitary fossa? Anatomical and MRI findings.

We compared MRI studies of the sellar area and embryological and adult histological studies of the cavernous sinuses and pituitary fossa. MRI studies were performed in 50 normal subjects with coronal sections using a fast inversion-recovery sequence to demonstrate the dural walls of the cavernous sinus and pituitary fossa. With this sequence, dura mater appears as a high-signal linear structure. The lateral and superior walls of the cavernous sinus was easily identified on all studies, but demonstration of a dural wall separating the cavernous sinus from the pituitary fossa was not possible. These results correlated well with embryological and adult histological studies obtained from 14 specimens. The absence of a strong separation between the pituitary fossa and the cavernous sinus explains the high incidence of extension of pituitary tumours to the cavernous sinuses and vice versa.

Adult↗
PubMed1998

High signal in the adenohypophysis on T1-weighted images presumably due to manganese deposits in patients on long-term parenteral nutrition.

Hypermanganesaemia is reported in patients on long-term parenteral nutrition. Deposition of manganese, giving high signal on T1-weighted images, may involve the basal ganglia. MRI in nine patients (mean age 51 years, range 31-75 years) on long-term parenteral nutrition (mean duration 30 months, range 6-126 months), demonstrated high signal in the anterior pituitary gland on T1-weighted sagittal and coronal images. The gland appeared normal on T2-weighted images. Signal intensity in the basal ganglia on T1-weighted images was increased in all patients. Endocrine assessment showed no significant abnormality. Neurological examination showed a mild parkinsonian movement disorder in one patient. Hypermanganaesemia was present in all nine (1.3-2.8 micromol/l, mean 1.87 micromol/l). The high signal in the anterior pituitary gland was probably related to deposition of paramagnetic substances, especially manganese.

Adult↗
PubMed1998

Interventional radiology with laser in bone and joint.

Laser energy is able to ablate, coagulate, and vaporize tissues. Its transmissibility in thin optical fibers makes it an ideal tool for use in percutaneous procedures. This article describes two applications in interventional musculoskeletal radiology. In percutaneous laser disc decompression the laser source is used to vaporize a small portion of the nucleus pulposus. In interstitial laser photocoagulation of osteoid osteoma the laser energy is used to coagulate and destroy the tumor by direct heating.

Adolescent↗
PubMed1998

Anatomy and embryology of the lateral sellar compartment (cavernous sinus) medial wall.

In order to study the microanatomy of the lateral sellar compartment (cavernous sinus) medial wall, serial histological sections of human fetuses and adults, as well as dissections under operative microscope, were performed. The results were compared to high resolution Magnetic Resonance Images in human, to microdissections and to serial histological sections in adult nonhuman primates (Papio Cynocephalus anubis). We were able to show that the sellar compartment and both lateral sellar osteodural compartments are not separated from each other by a dural wall, but by a more or less dense, interrupted, fibrous tissue which derived from the mesenchyme surrounding the hypophysis, carotid artery, cranial nerves and venous channels. In the human fetus, the previous mentioned structures are located in a unique interperiosteodural space. Histoarchitecture of the superior and lateral wall dura-mater was different from the underlying mesenchyme derived connective tissue and was easily distinguished through histological examination. These findings correspond to MRI data. We conclude that there is no medial dural wall limiting the lateral sellar compartment (cavernous sinus), both parasellar and the hypophyseal compartment should be considered as a unique extradural space. The only dense connective tissue surrounding the pituitary gland is its own glandular capsule and the periosteum.

Adult↗