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Biomedical subjects

P Gailloud

Publications and source records attributed to P Gailloud.

48 records · Page 3Linked to original sources

An in vitro anatomic model of the human cerebral arteries with saccular arterial aneurysms.

An in vitro model of the main human cerebral arteries with or without saccular arterial aneurysms is presented. A cast of the cerebral arteries was obtained in a human specimen. Three aneurysms were simulated and added to the cast. Wax copies of the cast were produced, and embedded with liquid resin solidifying into solid blocks. After evacuation of the wax, a model consisting of a hollow reproduction of the cast within the resin block was obtained. The model is reproducible and anatomically accurate. Since it is transparent to visible light, and compatible with x-ray, magnetic resonance and transcranial doppler techniques, it should prove useful for a wide range of haemodynamic and radiologic investigations. The reported technique may be adapted to any structure with a hollow configuration, allowing for the preparation of arterial and venous models from other vascular areas, as well as models from other anatomic systems, such as the biliary or urinary tracts.

Cerebral Arteries↗

A case in favor of aneurysmographic studies: a perforating artery originating from the dome of a basilar tip aneurysm.

A posterior perforating artery originating from the dome of a basilar tip aneurysm is reported. The exact origin of this perforator was identified by selective aneurysmography only. This observation provides an argument favoring the consideration of aneurysmographic studies before treatment of large aneurysms located in proximity to areas of normal perforating arteries.

Adult↗

Segmental anatomy of the liver: a review and a proposal for an international working nomenclature.

The segmental anatomy of the human liver has become a field of increasing interest to radiologists during the past few years. The number of different terminologies which have been used since the topic has been systemically investigated is, however, a source of serious confusion. The present paper describes the reasons why the authors plead for an international working nomenclature which distinguishes a right hemiliver consisting of a right posterior and a right anterior segment, formed by subsegments 6 and 7, and 5 and 8, respectively, and a left hemiliver consisting of a left medial and a left lateral segment, the former corresponding to segment 4, and the latter to subsegments 2 and 3. This basic concept, however, must be carefully tailored to the highly variable individual anatomy of each patient. Furthermore, some aspects of hepatic segmentation are not yet understood and require additional anatomical investigation.

Humans↗

Relationship between intrahepatic vessels and computer-generated hepatic scissurae: an in vitro assay.

Liver segmentation is a matter of increasing importance for radiologists, in particular with respect to accurate preoperative localisation of focal hepatic lesions. Procedures for delineating the segmental anatomy from CT or MR images are therefore much in demand. In this context, a convenient technique for generating the intersegmental scissurae by computer has recently been proposed [9]. The procedure, however, seemed questionable from an anatomical point of view. We therefore checked its relevance using anatomical vascular casts of post mortem livers and comparing the computer-generated scissurae with the actual course of the intrahepatic vessels. The results presented in this paper confirm that a rigid application of flat scissural planes is not able to render the real intrahepatic compartmentation. Only techniques considering the effective individual vascular anatomy can provide a correct determination of the hepatic segments.

Aged↗

Duplicated hepatic artery: radiologic and surgical implications.

Preoperative angiography of the coeliac trunk and superior mesenteric artery is routinely performed before liver resections and transplantations. For this purpose, it is usual to inject each branch of the coeliac trunk separately. Selective angiographic studies, however, may lead to overlooking surgically essential anatomic variations of the hepatic blood supply, as demonstrated by the present report. A case of a duplicated hepatic artery is presented, its radiologic and surgical implications discussed, and the relevant literature reviewed. This uncommon and particularly evocative feature illustrates the clinical importance of a sound knowledge of anatomical variants.

Adult↗

Three-dimensional reconstruction of a levator claviculae muscle.

During routine radiological examination of a 72 year-old woman a soft-tissue shadow in the left posterior triangle of the neck was observed. Three-dimensional reconstruction of this structure suggested that it might be a muscular variant: a levator claviculae muscle. In our case it took origin from the upper part of the cervical column and was inserted into the lateral third of the clavicle. With this example as a background, the general significance of anatomical muscular variants for modern imaging techniques is discussed.

Aged↗

Contrast-enhanced MR angiography: the effects of k-space truncation on luminal representation in a carotid artery phantom model.

Using carotid bifurcation phantom models with different degrees of stenoses, we evaluated the accuracy of vessel lumen representation on MR images obtained from the inverse Fourier transform of different k-space percentages. Our results show that the lower thresholds of truncated k-space sampling are dictated by the severity of luminal narrowing. The defined thresholds may help improve efficiency of 3D MR imaging of the carotid arteries while maintaining adequate luminal representation.

Carotid Arteries↗

Angiographic anatomy of the laterocavernous sinus.

BACKGROUND AND PURPOSE: The laterocavernous sinus (LCS) has recently been recognized as one of the major drainage pathways of the superficial middle cerebral vein (SMCV). Our purpose was to investigate the drainage pattern of the SMCV, with special emphasis on the angiographic anatomy of the LCS. METHODS: The drainage pathways of the SMCV were evaluated prospectively on 100 selective carotid angiograms obtained in 65 consecutive patients. RESULTS: The SMCV was absent in 19% of cases. A classic termination into the cavernous sinus (CS) was found in 20%, a paracavernous sinus in 39%, and an LCS in 22%. The LCS drained toward the pterygoid plexus (27%), the superior petrosal sinus (18%), the posterior aspect of the CS (32%), or a combination of these pathways (23%). A complete absence of connection between the LCS and CS was observed in 63.5% of the patients. CONCLUSION: The LCS is a laterosellar venous space that is anatomically and angiographically distinct from the CS. Secondary small anastomoses between the LCS and CS may make it difficult to differentiate the two structures. Appreciation of the course and connection pattern of the LCS is important, particularly when planning an endovascular approach to treatment of lesions in the region of the CS.

Adolescent↗

A panencephalopathic type of Creutzfeldt-Jakob disease with selective lesions of the thalamic nuclei in 2 Swiss patients.

Creutzfeldt-Jakob disease (CJD), a subacute spongiform encephalopathy, is generally included among the group of human and animal diseases which is transmissible by a non-conventional agent, the prion, whose expression is conditioned by the host's genome. The process leading to neuropathological changes is still unknown. We report the neuropathological findings in 2 cases of the "panencephalopathic" variant of CJD, which is relatively common in Japan, but extremely rare in Europe and North America. When compared with the classical form this variant is characterized by a relatively long clinical course with persistent vegetative state and primary involvement of the white matter presenting in the form of demyelination and gemistocytic gliosis. The selective involvement of certain thalamic nuclei is a particular pathological feature in both our cases. There was practically complete neuronal loss with diffuse gliosis of the anteroventral (AV) and dorsomedial (DM) nuclei, while the neuronal loss in the pulvinar remained moderate: the other nuclei were apparently spared. A similar involvement of the thalamus has been reported in fatal familial insomnia, a recently described prion disease in which these lesions are predominant. A comparable distribution has also been observed in other degenerative neurological diseases such as Steele-Richardson-Olszewski disease, Alzheimer disease, and thalamic dementia (selective thalamic atrophy or with multisystemic degeneration). The AV and DM nuclei, commonly referred to as "limbic thalamus" represent phylogenetically the most recent thalamic structures and would appear to play an important role in the superior functions in man as memory, attention and awareness. In our cases thalamic lesions are selective, bilateral, and symmetric, not explained by Wallerian degeneration. These lesions may be due to the primary pathogenetic properties of the infectious agent. The rapid clinical evolution in a persistent vegetative state could be consequential to precocious and severe disfunction of the limbic thalamus.

Creutzfeldt-Jakob Syndrome↗

Adhesion molecules in HIV-related and idiopathic polymyositis: immunohistochemical studies.

Idiopathic polymyositis (IPM) and HIV polymyositis (HIV-PM) are considered to be related autoimmune diseases whose target is skeletal muscle. They have been associated to a T cell-mediated and MHC-I-restricted cytotoxic phenomenon, but both etiology and physiopathology remain incompletely understood. Their histological hallmarks are mononuclear leukocyte infiltrates as well as necrosis, degeneration, and regeneration of muscle fibers. In the present study, we have investigated the immunohistochemical expression of cell adhesion molecules, cytokines, and leukocyte surface antigens in biopsies of HIV-PM and IPM patients. The aim was to better define factors involved in lymphocyte recruitment and in inflammatory changes seen in PM. Notable upregulation of ICAM-1 and TNF-alpha was detected on capillary and venular endothelia and on inflammatory cells, whereas no significant VCAM-1 and ELAM-1 expression was present. LFA-1, the main ICAM-1 counter-receptor, was found to be highly expressed on lymphocytes and monocytes, especially at the vicinity of damaged fibers. The majority of infiltrating cells were CD8+CD45 RO-T cells, which are thought to have memory capacities. These findings suggest that in IPM and HIV-PM, enhanced ICAM-1 and LFA-1 expression possibly induced by TNF-alpha, may regulate the homing process of selected lymphocyte clones in muscle tissue. Lymphocyte proliferation and differentiation into memory subsets may further potentiate tissue-restricted homing capabilities.

Adult↗

Direct emergence of the dorsospinal artery from the aorta supplying the anterior spinal artery: report of two cases.

We report two cases of an isolated dorsospinal artery that emerged directly from the aorta to supply the anterior spinal artery, which in one case had another blood supply on the opposite side, in a lower position. It is important to identify this anatomic variant, otherwise spinal angiography might be incomplete, especially when the isolated dorsospinal artery supplies the anterior spinal artery.

Adult↗