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Biomedical subjects

L Remonda

Publications and source records attributed to L Remonda.

64 records · Page 4Linked to original sources
PubMed1996

[Spinal stenosis: current aspects of imaging diagnosis and therapy].

Lumbar spinal stenosis typically manifests itself through low back pain and neurogenic claudication during walking. Cervical spinal stenosis may manifest itself through a multitude of symptoms. Spinal stenosis is classified into congenital or primary and acquired or secondary forms. Conventional X-rays of the spine often reveal only unspecific findings. Computed tomography (CT) is the preferred method of judging the width and anatomy of the spinal canal. Myelography remains a good method of imaging the spinal cord in its entirety and in addition allows functional imaging of the width of the spinal canal with functional stress images. CT performed directly after myelography (myelo-CT) allows specific imaging of areas still unclear. Magnetic resonance imaging (MRI) allows multiplanar imaging of the spine and better soft tissue definition. Surgical therapy is discussed in relation to the clinical and neuroradiological findings.

Aged↗
PubMed1996

Preoperative embolization of paragangliomas and angiofibromas. Measurement of intratumoral arteriovenous shunts.

OBJECTIVE: To determine if technetium Tc 99m-labeled macroaggregated albumin selective angioscintigraphy enables estimation of microparticle-arteriovenous shunt in branchial paragangliomas and nasopharyngeal angiofibromas. DESIGN: Technetium Tc 99m-labeled macroaggregated albumin particles with calibrated diameters between 25 and 50 microns were administered during selective catheterization of the feeding arteries in 4 branchial paragangliomas (glomus tumors) and 4 nasopharyngeal angiofibromas. Preliminary measures of the activity of the tumor region and of the lungs were obtained in the angiography suite using a hand-held detector. Without changing the position of the microcatheter, definitive embolization was performed. After endovascular treatment, scintigraphy was performed and the pulmonary shunt index was calculated with the use of a gamma camera and a dedicated computer program. RESULTS: The pulmonary shunt index varied between 0% and 36% for branchial paragangliomas (glomus tumors) and between 82% and 95% for angiofibromas. CONCLUSIONS: Our results provide new evidence that the incidence of microparticle-arteriovenous shunt in nasopharyngeal angiofibromas is much higher than in paragangliomas.

Adolescent↗
PubMed1995

[Neuroradiology--past and future].

After the discovery of X-rays by Roentgen exactly 100 years ago, neurosurgeons and neurologists have been promoting an imaging diagnosis of the central nervous system around the turn of the century with methods like pneumencephalography and angiography. With the induction of computed tomography and magnetic resonance imaging (MRI) in the last two decades, seemingly simple examination methods became available which led to a temporary separation of neuroradiology from its parent fields. Further development of MRI with methods that allow to measure brain perfusion and to visualize brain function has led this diagnostic modality back to its origin, neurology: adequate evaluation of such multimodality imaging is only possible in the context of all neurosciences. On the other hand, interventional neuroradiology with endovascular procedures in the brain has evolved to an operative field that is only feasible in close cooperation with neurosurgery. This also applies to MRI, where the 'open magnets' require close cooperation between neuroradiologist and neurosurgeon to perform image guided procedures online.

Angiography, Digital Subtraction↗
PubMed1995

[Diagnostic tomodensitometry of acute basilar thrombosis].

Basilar artery thrombosis is a potentially treatable neurologic disease whose initial symptoms are sometimes difficult to recognize. The basilar artery is hyperdense on computed tomography in cases with basilar artery thrombosis. We have studied computed tomography attenuation values before and after contrast administration in a total population of 117 patients, 12 of whom were diagnosed angiographically as having basilar artery thrombosis. While it is not always possible to detect basilar artery thrombosis simply by evaluation of the tomodensitometric values before or after contrast, the differential values obtained by subtracting them (after contrast/before), or by an attenuation ratio corresponding to the differential value divided by the value before contrast, are more helpful. Indeed, the differential values and attenuation ratios in the normal population have a mean value of 51.1 and 1.37 compared with 14.47 and 0.33 in patients with basilar artery thrombosis.

Aged↗
PubMedDate not supplied

Dural ectasia of the optic nerve sheath in neurofibromatosis type 1: CT and MR features.

OBJECTIVE: Optic nerve glioma is a common finding in patients with neurofibromatosis type 1 (NF-1). Although dural ectasia of the optic nerve is encountered rarely, it has to be considered in the differential diagnosis. MATERIALS AND METHODS: Three patients affected by NF-1 were examined sequentially by CT and MRI. RESULTS: Computed tomography demonstrated nonprogressing enlargement of the anterior optic pathways. Magnetic resonance imaging displayed widening of the perioptic dural sheath without any suggestion of tumor. CONCLUSION: These findings are compatible with meningocele or dural ectasia of the optic nerve sheath. This entity represents a differential diagnosis to optic glioma in patients with NF-1.

Adolescent↗
PubMedDate not supplied

Facial intraosseous arteriovenous malformations: CT and MR features.

OBJECTIVE: To present the CT and MR findings of two patients with maxillofacial intraosseous arteriovenous malformations (AVMs) before and after endovascular therapy. MATERIALS AND METHODS: Two young girls suffering from AVMs in the maxilla and mandibula with spontaneous bleeding in the oral cavity were examined by CT and MR on a 1.5 T GE unit before and after selective endovascular embolization. RESULTS: Computed tomography using a high-resolution algorithm and two-dimensional reconstructions demonstrated the morphology of the bony lesions as well as the regrowth of the bone after successful embolization. Magnetic resonance was the best imaging technique to show vessel structures and the accompanying soft tissue changes. Angiography showed the exact angioarchitecture of the AVM and was essential for therapy planning. CONCLUSION: Because selective endovascular embolization of maxillofacial AVMs is gaining in importance, CT and MRI are, therefore, essential for diagnosis and therapy planning as well as for follow-up imaging.

Arteriovenous Malformations↗
PubMedDate not supplied

CT cisternography in congenital perilymphatic fistula of the inner ear.

Perilymphatic fistulas of the inner ear constitute abnormal leaks of perilymphatic fluid into the middle ear or mastoid air cell system and represent a rare cause of otorrhea. We report the case of a 5-month-old child presenting with sudden otorrhea. High resolution CT cisternography showed a malformation of the middle ear and a passage of contrast-enhanced CSF into the tympanic cavity through the left oval window. Surgery confirmed a tear of the tympanic membrane as well as a stapes malformation with aplasia of the crura and an associated perilymphatic fistula through a defect in the stapes footplate. The fistula was closed with adipose tissue from the ear lobe.

Cerebrospinal Fluid Otorrhea↗
PubMedDate not supplied

A dedicated animal model for mechanical thrombectomy in acute stroke.

BACKGROUND: Recent studies have focused on mechanical thrombectomy as a means to reduce the time required for revascularization and increase the revascularization rate in acute stroke. To date no systematic evaluation has been made of the different mechanical devices in this novel and fast-developing field of endovascular interventions. To facilitate such evaluations, we developed a specific in vivo model for mechanical thrombectomy that allows visualization of dislocation or fragmentation of the thrombus during angiographic manipulation. METHODS: Angiography and embolization with a preformed thrombus was performed in 8 swine. The thrombus was generated by mixing 25 IU bovine thrombin and 10 mL autologous blood. For visualization during angiography, 1 g barium sulfate was added. RESULTS: The preformed thrombus exhibited mechanical stability, reproducibility, and high radiographic absorption, providing excellent visibility during angiography. The setting allowed selective embolization of targeted vessels without thrombus fragmentation. Despite the application of barium sulfate no local or systemic reaction occurred. Histologic evaluation revealed no intimal damage caused by the thrombus or contrast agent washout. CONCLUSION: The model presented here allows selective and reliable thromboembolization of vessels that reproduce the anatomic and hemodynamic situation in acute cerebrovascular stroke. It permits visualization of the thrombus during angiography and intervention, providing unique insight into the behavior of both thrombus and device, which is potentially useful in the development and evaluation of mechanical clot retrieval in acute cerebrovascular stroke.

Acute Disease↗