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Biomedical subjects

N S Polli

Publications and source records attributed to N S Polli.

7 recordsLinked to original sources
PubMed1999

[Usefulness of selective partial inversion recover (SPIR) sequences in optic nerve diseases].

PURPOSE: To evaluate the yield of SPIR sequences with fat suppression in the diagnosis of optic nerve lesions. MATERIAL AND METHODS: Ten patients with suspected optic nerve involvement on the basis of clinical data and abnormalities of visual evoked potentials were examined. MRI was performed with a 1.5 T unit (Philips NT 15) using T1 weighted conventional spin-echo and T1- and T2 weighted SPIR sequences with fat suppression. Axial images were obtained along the optic nerve course, while coronal images throughout the optic nerve axis; slices were 3 mm thick. Axial T2 weighted SPIR sequences were also performed with the volumetric technique (1.5 mm thickness); coronal and parasagittal reconstructions along the nerve axis were obtained too. After paramagnetic contrast medium injection, conventional T1 weighted and SPIR sequences were performed on axial and coronal planes. RESULTS: Optic nerve lesions consistent with the diagnosis of neuritis were demonstrated with T2 weighted images in 4 of 10 patients. No abnormalities and/or nerve enlargement were found on T1 weighted images. An enhancement area was seen after contrast medium injection in only one case. MRI showed a pilocytic astrocytoma in one patient and selective atrophy of the right optic nerve in another. MRI showed normal findings in 4 patients. CONCLUSIONS: T1 and T2 weighted fat-suppressed SPIR imaging of the optic nerve improves anatomical definition, lesion detection and characterization in optic nerve conditions.

Adult↗
PubMed1992

[Causes and incidence of short-life keratitis caused by dacryography. Optimization of protective parameters].

This study was aimed at investigating the changes occurring in superficial corneal epithelium (localized or diffuse, dotted or linear) as observed in 300 eyes after macrodacryography with iodate contrast media (iodized oil and water soluble non-ionic agents). In our opinion, the causes of iatrogenic short-life keratitis are: needle injury, the deposition of iodate contrast medium on the cornea and the reduction of palpebral winking, favoring dry eye, due to superficial anesthesia. The pharmacologic protection of the cornea by means of high-viscosity drugs allows both the number and the degree of keratitis to be markedly reduced. Therefore, contrast media must be chosen on the basis of anamnestic and clinical data, as well as of patient's symptoms, focusing mainly on the characteristics of the various agents--i.e., density, concentration, viscosity.

Humans↗
PubMed1988

[Does a iatrogenic damage caused by dacryography exist?].

This study was aimed at investigating the changes in corneal epithelium caused by dacryocystography. Such changes can be either chemical--from iodate contrast media (iodized oil and water-soluble non-ionic cm)--or physical--from needle or catheter. Twenty-five patients (50 eyes) were studied using BUT, Schirmer tests, biomicroscopy, and pachymetry. Follow-ups immediately after dacryocystography demonstrated superficial keratitis, which was less severe with water-soluble non-ionic cm. Such lesions were hardly ever observed in patients who had been treated with dacriosol ointment on the cornea just before the X-ray exam. Follow-ups at 24 hours showed the superficial keratitis to have disappeared in all patients, independent of the kind of cm employed and of the ophthalmic ointment applied to the cornea.

Adult↗
PubMed1986

The radiation dose to the lens in radiology of the orbit.

This paper describes research into measurement and reduction of the radiation dose to the lens during various examinations, namely skull and orbit, optic canal and optic strut, superior and inferior orbital fissure, localisation of foreign bodies in the eye, calcifications, orbital fractures, macrodacryography and orbital venography. Using rare-earth screens and high-sensitivity films, without an antiscattering grid, and with an added filtration of 0.5 mm Cu, it is possible to reduce the radiological risk during all investigations involving skull, orbit and eyeballs, while maintaining a good image quality. Particularly in those examinations with direct magnification (macrodacryography and venography, foreign bodies in the eye, orbital fractures), the dose to the lens is very low: less than 0.2 mGy/radiograph.

Eye Diseases↗
PubMed1985

[Role of sophisticated radiological technics in the diagnosis of lacrimal fistulas].

Lacrimal fistulae are rare and not well known by radiologists. Four cases are illustrated, two congenital (a skin-canaliculous and a canaliculous-palpebral fistula) and two acquired (a rare case of sac-orbital fistula and a canaliculous-palpebral fistula arisen during dacryography). Fistulae are to be distinguished from pedunculated lacrimal diverticulous of which an interesting and rare case is presented. After a careful examination of the pathogenesis and symptomatology of lacrimal fistulae the authors agree that only macrodacryography carried out by means of sophisticated techniques (seriography, magnification, subtraction) enables a precise demonstration of the originating point, of the course and outlet (cutaneous and internal) and provides therefore indispensable data for surgery.

Adolescent↗